Definitely a difference. 50NL is where you start to find the good regs, those who have worked themselves up from the lower limits and have learned a lot more about the game. They're now starting to get clever. As was mentioned, 3bets are more frequent, they're trappy, they'll float you a lot more to rope-a-dope you, etc., and they're getting good enough to lay down 2nd best hand a lot of the time, unlike at the lower stakes where you can valuetown most of the bad players who can't fold middle pair.
There are some very good regulars at 50NL. Even 25NL has a lot of decent grinders that will outplay a 10NL player. Jumping straight from 10NL to 50NL if you're only b/e now would be a huge risk, I think.