Things to think about -
How many people do you want to fit in it?
What kind of seating do you like? I’ve decided that I really dislike the recliners. If it’s not something your going to use, and takes up lots of space, avoid it.
Do you want bubbles? The tub I bought years ago had both jets and air bubbles. I hated the air bubbles, as it piped in unheated air. Goodie, cold bubbles up my back.
Consider a tub with a timer - Do you envision yourself using the tub every evening at 10PM? Then a timer that starts the heat up process at 9pm automatically might be the way to go.
Insulation - you don’t show where you are located. The tub I bought went in northern Michigan. Having a well insulated tub was a requirement.
I’ll second Rick’s suggestion of an ozone generator. It’s rather nice being able to use a lot less chemicals. Also a good call on the lift cover. Who wants to wrestle with the cover after getting out of tub?
Also take a look at used tubs. I’ve been hearing that there are a fair number of people who find they don’t actually use the hot tub, and decide that rather then letting it rot in the backyard, they would sell it. I also know that one of the local dealers takes trade ins, so I’m assuming they sell them off somehow.