I found the Razor Code to play noticeably softer. It pockets the ball more and feels more forgiving. Ruff Code is a firm and crisp playing string -- something I like. I felt very connected to where my shots were going with it, but it is not as forgiving off center as Razor Code.
If you want a bit more juice, ball pocketing and comfort, Razor Code is the way to go. If you like a firmer, crisper response, Ruff Code is the better option. Ruff Code is much closer to Black Code, whereas with Razor Code you are moving towards the realm of softer co-polys.
Hope that helps,