I have to be honest, I think the market is completely saturated with character sets in general. I look at the new releases in the RMP every day, and get disappointed when I see new character packs. I would much rather see clothes or props for the DAZ figures than actual characters themselves. You'll only ever need so many textures, after a while they get pretty redundant in terms of usefulness in your library. I also think half the fun of poser is coming up with your own combination of morphs to make a figure look unique. That being said, David is probably the most underepresented in terms of character packs. At the same time he's as versatile as M3 if not more so because his muscle morphs look a lot more realistic. I've found you can make V3 look like almost anyone with both the face and body morphs. The same cannot be said about SP3 (in my opinion), so she ends up being a lot less useful (as would any character packs for her). Also, since V3 textures work almost perfectly with S3, and there's a deluge of them in the RMP, S3 character packs aren't nearly as useful for that reason as well.