I typically fill 14 to 16 large leaf bags when I rake the yard. It varies depending on how much I pack the bag. Dad would pack his to the point that a bag would weigh 30 lbs. 
Blowers with a mulch/vac claim about a 10 to 1 reduction. Meaning, I guess, that I’d used maybe 5 bags? (I don’t take that ratio literally)
But, how heavy would that bag be? If you’re mulching and removing air. Are we talking sixty lb bags of mulched leaves?
Also, how effective is mulching on pine needles? Do they mulch at all or stay the same size? I have Poplar and Maple leaves in the front and pine needles in the back yard.
Mulched leaves are denser, so yes the resulting bags are heavier. Of course, if you’re a serious stomper, I suspect you can stomp the same amount in either way.
My Riobi doesn’t handle loblolly pine needles very well, though it’s been pretty good on leaves. I find it’s faster and easier to rake them. Also, they don’t composte very well (part of what makes them good mulch).
Loblolly pines have long needles much like a red pine. You might have better luck with shorter bushier needles like white pine, but only if it’s a pretty heavy-duty tool.
And yeah, don’t believe the 10 to 1 ratio. It’s closer to 2 to 1 or maybe less, but I’m a stomper.
In general, a rake is quicker, but a lot more effort.
You’ve got it right. The weight increase will match the compression ratio. If you cram in 5x as many leaves, that bag will weigh 5x as much.
As for pine needles, they’re generally broken down to the same size particles as leaves. Which means each needle only gets divided into 2-4 pieces.
I’ve had the best luck going slowly with a bagging mower. Of course, if you’ve got one of those that has the small opening for stuff coming in as stuff dumping out, it doens’t work so well.
Thanks.
I’m looking forward to getting some mulch for the flowerbeds. The maple and poplar leaves should make some nice mulch.
Most of the leaf material with pine needles will get bagged and set out on the curb for pickup.