First of all, nobody ever looked inside of M32 as of yet (I doubt MIDAS will release any internal pics), so all these "different or not" talks are guessing and hearsay. Fact that DL16 and S16 look identical doesn't mean anything. It's a lot cheaper to make a new printed board than a new metal enclosure, it seems pretty logical to put a new preamps in the same metal box already being made for S16. Chase McKinight from MIDAS stated that M32 preamps are MIDAS Pro and are 96K capable (see above in this thread). We have to trust MIDAS at this point, until someone from our community will test DL16 against DL251 and S16, to tell how much the difference in sound will be.
Second, all this 96K vs 48K talk, how it is really important for sound quality? Theoretically -- yes, on real club-level gigs -- I'm not sure, there are so many other factors involved. Badly tuned PA will make crappy sound with any desk. Besides, the preamps design itself, its analog circuitry before signal hits the A/D converters, differs a lot from one preamp to another and makes more difference. You can get M-Audio preamps for under $100, or Apollo for $2K, or AVID Omni for $5K, they all are 96K. Why there's so much of a price difference?
Every tool has it purpose, my X32 already paid for itself after only a few weekend gigs. If I had Pro-2c with DL251 I'm not sure how long it would take me. X32 makes bands and whoever writes the checks happy. I may get Pro-2c just because I like the desk, from business standpoint it doesn't make any sense, at least for my gigs.