Haven't used D2 yet, but from what I've been able to read up on it, M2 will keep its edge longer (on the downside, though, it'll be more prone to rust). My M2 blades (710HSSR and Ritter Mini-Grip) have indeed kept their edges an insanely long time. Haven't yet tried sharpening them, though.
M2 may keep its edge noticeably longer than S30V or 154CM, etc., but I think you'd find great performance in any of Benchmade's steels. The only steel of theirs I haven't liked much is ATS-34 (which they don't use anymore), as it took me forever to sharpen, compared to my S30V and 154CM BMs.
And for a survival/utility knife, I would put my vote in for the Ritter Grip. For one, that's exactly what it's designed to do, and secondly, rust resistance would be an important quality in a survival knife to me (meaning I would take S30V over a knife in D2 if possible).
M2 may keep its edge noticeably longer than S30V or 154CM, etc., but I think you'd find great performance in any of Benchmade's steels. The only steel of theirs I haven't liked much is ATS-34 (which they don't use anymore), as it took me forever to sharpen, compared to my S30V and 154CM BMs.
And for a survival/utility knife, I would put my vote in for the Ritter Grip. For one, that's exactly what it's designed to do, and secondly, rust resistance would be an important quality in a survival knife to me (meaning I would take S30V over a knife in D2 if possible).




