I like both the 600 and the 13. The 600 I like because the build quality is more solid than a naga, but I also don't use all the side keys. So I can't answer that. It is easy to tell where my thumb is though, they're angled slightly differently (the first 2 rows and last 2 rows are all set so that the 'inner' part of those rows are lower, so it's likd two ridges of keys) and there's a bump on the center 2 keys.
The 13 I just always use when I play, almost every game. I only take my hands off of it to type in wow.
The 13 I just always use when I play, almost every game. I only take my hands off of it to type in wow.