I’ve been intimately involved with two cases - both complex - from start to finish - and plenty more on not as detailed a level.
On the state level - the PD in question simply did not have time to spend on any real cases. He handled 350 the year prior and took 10 cases to trial. He won half of those. Keep in mind that the state/Feds have enormous leverage. It is almost always “let’s make a deal”. I’m not sure how much work was put in on the case - there was lots of pressure on the PD, but he appeared to do very little. I’m talking maybe four phone calls with the defendant - who wrote numerous letters - and the prosecution had about 40 witnesses show up the day of trial - and the PDs lack of effort made it implausible & too risky for anything other than a plea deal. I would guess he spent maybe 5-10 hours MAX on the case. This was probably in the top 10% of cases in terms of complexity - and only cause the defendant was basically planning on going to trial until the other two defendants caved on the day of trial.
On a federal case - it was completely different. Ok - it was me - and I REALLY didn’t do it. It was also an extremely complicated case. He actually met me when I was first bright in before the court (and initial conditions were set). I had numerous in person meetings and telephone calls. He actually came to my apartment - with an investigator (like a PI, but only worked for their office I think). He also got a technical person (computer forensics) as well as hired a polygrapher. I had hours long telephone conversations and he spent I have no doubt at least 100 hours on the case. He remembered even the smallest details and was the sharpest lawyer I had ever met. He often would explain his rational behind moves he was making - and I was impressed. We went on a ride with the PI guy to various locations in multiple counties so he could get a feel for everything. He had flows charts and stuff. Even bought me breakfast one time. He told me his case load - and had some great stories - I am not sure the exact number he told me - I think it was either 60 or 45 a year.
He kept me updated all the time and some really weird things happened. His brother happened to be a writer for a magazine I won’t mention. He was in a certain place - and actually overheard some of the agents involved talking about my case (it was a very unique set of facts). There was other stuff like that - like - well let’s just say someone who worked for the other side - shall we say - sent me something by mistake (have to be vague here, but imagine something was supposed to go to a lab - and they mailed it to me by mistake). It was kind of like that. We didn’t do anything unethical - and something else happened that rendered that problem moot. He ended up convincing them of their mistake - they dropped the case - with prejudice - and gave me back every single thing they had seized.
Anyway - my codefendant was unfortunate - in that I got to the Public Defenders office first. He was appointed an attorney, but I think they wouldn’t give him a PD cause it was a conflict or something. So he was on a list of volunteers (who still got paid, but not much). He was awful. No home visits, long phone calls, flow charts. He knew virtually nothing about the case and was only trying to get a deal. Codefendant was probably technically guilty of something - and ended up pleading guilty, but the case was so ridiculous - that while he was facing the possibility of 75 years - he got 45 hours of community service (or close to it - don’t remember the exact number, but think it was ~ 45).
If I was ever arrested - or knew someone who was - in the Federal System - I walk run to the Public Defenders office. I could tell that they are dedicated public servants - and give a shit and try their best AND have resources to do so. I can’t think of any case off hand I wouldn’t use them for - except maybe complicated securities fraud - or massive, massive drug king pin stuff (and I might still use them for that). I would even pay for them to represent me.
On the state level - I do know quality public defenders and have had lunch with a couple while watching cases. I remember one I’d run into - maybe saw her a dozen times in court. She’d tell me stories how shed use her own money to get defendants a dress shirt to court to cover up their tattoos in court. I saw her represent this one guy in a jury trial - they had him on video, fingerprints, eyewitnesses, and an almost confession (don’t remember - but it was bad). As you can imagine the state wasn’t really willing to cut him much of a deal (I found out later) - so he thought what the hell - might as well take a chance of getting off - vs guaranteed 14 years vs maximum 15 years (I think it was numbers like that).
After I saw/heard the States opening statement - I thought - holy shit - what the hell is she going to do. She basically got up there and did her best to kind of say - hey - yeah they got lots of stuff, but they don’t KNOW it’s him and it won’t meet the test for reasonable doubt. Something like that.
I made some smart ass comment about her having gotten pretty unlucky with that one - and we joked about it. She really did care about the role of a zealous defense in an adversarial system. She unfortunately didn’t have the resources or time to give everyone as much time as she needed. She moved to a different county and I think I only ran into once after that. She said it was great as before she had no time - and was representing people accused with rape and murder that needed time - and now she had more time - and was getting cases like fishing without a license (I think she was working felonies only before - and then was doing both at the new place, but not sure).
Anyway - I have no doubt she could do a good job, but wouldn’t have the time in the first county, but would in the second. I still think she’d be stuck on resources. I’d find out what the average case load is - if you are dealing with hundreds of felony cases a year - you need a private attorney if you are going to try and plead not guilty - go to trial.
As someone else mentioned - the one thing the Public Defenders have that works in their favor is experience on what is a good deal. But many private attorneys can call and get this info from a friend who works in the Public Defenders office. I got the impression from the Federal Public Defender - that they often answered questions of this nature from private attorneys - especially ones court appointed - as federal cases are relatively rare - so even most private Criminal Attorneys aren’t doing many federal cases.
If the case is straight forward - and you aren’t looking at much time - you might be better off with a public defender. But I would not use (if I had a choice) an attorney taking 300+ felony cases a year in the state system, but it would depend on the county.
I have sat and watched in court - and I’ve been more impressed with the private attorneys at the state level. I also saw some awful ones as well. I’m guessing they weren’t specializing in criminal law, but they got hired cause it is a friend of the defendants uncle or something.
In other words - I think you get a sort of minimum level of competence with the state public defenders (in many cases).
If you ever need to know - you can learn a lot from just sitting in court observing that jurisdiction. Of course if you REALLY need to know - you might not be able to 
Oops - I kinda droned on.
TLDR - in the federal system - very few attorneys are going to be specialized enough to have the experience to match a federal public defender
At the state level - it is going to vary dramatically based on case load - and how much they allocate on resources. In my area - it’s an extremely small amount of cases taken to trial - so the Public Defenders aren’t necessarily going to have a lot of experience with actual jury trials. I tend to think people are more likely to hire a private attorney when they want to go to trial (yeah I know this is based on income, but relatives pay and stuff).
So I’m guessing - with no real proof - that a private criminal attorney takes a greater percentage of cases to trial than a public defender. This may be cause if Aunt Judy doesn’t think Bobbie is being offered a good deal by the state - she will hire him an attorney (who will have either told aunt Judy & Bobby ahead of time - hey I think it’s a good deal you should take it OR I can do better).
