I had a SD702 and thought it was a nice recorder but the preamps where not as good as the Grace pre amps nor my PSP-2 (although that is an entirely different design).
I sold mine because IMO it was not the All in one I was looking for and I would always want to run a Pre infront.
Zaxcom is supposedly going to support up to 96Khz and possibly 192 - it's just not shown so in the current specs.
x2
I owned and ran both the 722 and later the 702. While I thought they sounded very good as all-in-one boxes, I still preferred my V3 in front. Later I sold the V3 and got a PSP2 and also preferred it to the 7xx preamps. I had always been feeling that the 7xx had a bit more bloated or loose bass/low-end (just a tiny, tiny bit, but enough that I preferred the V3), but that may be because I was comparing it to the V3 that I had been running for years before getting a 722.
As Itgoes11 has been saying lately, it may be that the V3 rolls the bass off a bit. That may well be the case, and it might be that the 722 is actually more accurate than the V3. But I almost exclusively record PA-driven concerts with overblown subwoofers cranking, so the V3, rolloff or not, sounded better to me than the 722.
That said, to me the 722/702 along with the V3 were the favorite pieces of gear I've ever owned (well, excluding mics). Just fantastic pieces of art, design, engineering, implementation, etc. I totally see the price SD gets for the 7xx boxes, I just don't see as much the need for that as a hobbyist concert taper. I'm disappointed if I screw up a recording, but nobody is ever relying on me and there are almost always other tapers out recording anyway.
For me, I bought a Sony D50 -- also one of my favorite pieces of gear -- totally rock solid and reliable after years of taping. The optical digital connection is a bit of a concern (though I haven't had a problem), but the D50 has been 100% reliable, and also well-engineered and good sounding. Anyway, I sold the 702 for about $1700 iirc, bought the D50 used for $350, and with the difference was able to buy a used set of Gefell m210 hypers.
I loved the 702/722, but I don't ever see going back. Rather have more mics and preamps at my disposal.