If I owned a V3 or MME or something, one of these would be in my bag.
lets see....
V3 = $1500
Maudio = $350
4gbs of flash = $400
or a 722.
take your pick. I guess i'd go w/the 722 at this price range just for hdd space.
The 722 is definitely an option. But if you already have a V3, you're looking at selling it used for $1000-1200 and then needing to buy a new 722 for ~$2400(?) fully equiped. And you can get a 4gb Kingston CF for $275 (and only $150 for a 4gb microdrive, though I don't know if that works or what the battery life implications are).
So:
new 722 after selling used V3 for $1200 = ~$1200 out of pocket cost
or existing V3 with new MAudio ($350) + 4GB CF card ($300) + 30GB OTG drive for CF transfers and increased storage ($80) = $730 out of pocket
Bottom line, if you've already got a V3 you'd like to use, the V3 + MAudio package is a lot cheaper. Not to much terribly worse in terms of size (assuming you're doing open taping or even fob). And then there is the sound, if you already like the V3 sound, why change to something else?
Not at all trying to start another one of these 722 battles, but I've been going through all this myself recently and the V3+MAudio combo has a lot going for it. Really depends on how you value different things and what you're starting point is.