So much has changed in the recorder department, I still remember when reliable 4-channel 24/96 was just a pipe dream!
I would listen to as many Sound Devices MixPre samples and Zoom F series samples as possible. Throw in some Sound Devices 700(?) series samples as well.
A few years ago I finally upgraded my home playback to some (semi) serious studio monitors + DAC and it made a huge difference in critical listening for me.
I absolutely am biased, based on my owning (and loving) an F3 and F6, but I did a lot of listening and I preferred the Zoom F series before buying them. The difference is subtle but I liken the Zoom preamps to a V3; clean and transparent. Minimal-to-zero coloring of the sound.
While the MixPre preamps aren't very colored to my ears, they're just SLIGHTLY (I repeat SLIGHTLY) dull. This could be a lack of brightness. It is definitely subtle, but I hear it. I have heard plenty of MixPre recordings that I thought sounded great, and I have no doubt you could make great recordings with them. It's entirely possible the Zoom preamps have just a hair of that classic high-frequency bump (presence) that most people like. I know I like it. The Zoom and SD recorders both have excellent noise performance, see specs. I've only listened to a few of SD 722 samples and I liked them.
It sounds like SD's service is better and I know the MixPre's are engineered VERY well; they're using 3 separate ADC's, set at different gain stages, and the recorder selects the ideal ADC based on the incoming signal level. This applies to 24-bit and 32FP recording mode. The Zoom's use 2 ADC's for a similar feature. Both have proven to be reliable in the field.
32-bit Floating Point (32FP) is a whole other animal; good luck haha. Just know that the main difference is that you do not set your levels when using 32FP. There is not a sonic benefit to using 32FP over 24-bit. IMO, do not fear 32FP. It is super useful when I setup close to the stage/performers and I can hit record well ahead of time and not interfere with the performance while messing with levels. The performers appreciate it and I'm allowed to record a lot of great musicians because they know I stay out of the way. Or hitting record early at a rock show and wandering the venue and enjoying the performance has been priceless for me, I truly tape more now.
If you're only gonna be doing 2 channel work for the forseeable future, I recommend just start out with an F3. Tiny, cheap, simple and sounds great. A tiny 5000mah cellphone battery off Amazon and it will run 10+ hours.
The good news is I don't think you can go wrong with any of the above recorders. We should celebrate so many wonderful options.