The Sound Devices 702 was probably the single nicest piece of hardware that I've owned that just felt and looked bomb proof and designed with really high quality engineering. WAY BETTER than a Zoom anything. That's not to say that I haven't owned nice things before, but Sound Devices really makes high quality, rugged stuff that is high quality and rugged because it needs to be, not because it makes weekend warriors feel good.
I am actually looking at getting a recording interface again and was just looking at the MixPre-3 yesterday haha.
What I don't know about the MixPres is how well they work as recording interfaces. The series was originally designed to be for on location sound mixing, but now with all the advancements in technology, are recorders and computer interfaces as well. Presumably they are decent in those roles (I see the 7 series recorders are no longer made), but they might not have the nice Windows/Mac companion app to help you set it up for computer recording. You might be messing around with the little menu on the device itself.
Last thing about them - a lot of cheaper interfaces don't list the amount of gain on the mic preamps. Sound Devices does, and it's a pretty large range, up to 76 dB. Most companies wouldn't provide that much available gain if it wasn't quiet. I've not used this new generation of mic preamps by them, but have used the previous two (old Mix Pre series and the 7 series recorders) and the mic pres in both of them were very serviceable. A lot of gain and quiet.