In terms on neck profile, you'd like a 2008 and up RG1527
the most. The neck is still thin, but a lot rounder on the back. Much more comfortable in my opinion.
I have owned both an RG1527 and an RG7620 at the same time. I'd take the RG1527 hands down. The only downside is that the Edge Pro is a LOT harder to set up than the Lo-Pro Edge. I have no idea why. But it was every bit as smooth and stable once it WAS set up.
Oh, well if you're going to block it anyway, then definitely get the RG1527. No questions asked.