I bought this to replace the Das Ultimate keyboard: /t/24748
They're both using MX Brown, but they feel noticeably different.
The key travel on Razer is shorter than Das, make it better for gaming, the full travel distance is about the same, but if you press them in exactly same way, the Razer will register your key press first.
The sound is also different, Razer one makes a more clicky sound, while Das one sounds more subtle and dull. I personally prefer the Das one though.
Typing speed: I use typrX (Das sponsored) for speed measurement. When I was using Das, I rarely drops below 60 wpm (I knew I suck). Just bought the Razer, so right now it's not a fair comparison, but currently I'm around 55 wpm. Even though I dropped 10%, but that are largely due to mistyping.
Pros about Razer: Mac layout right out of box. Although the function keys won't work without driver. Macro keys for gaming. (Cannot wait for GW2, yay) Cheap, only $80 compare to Das's $120 price tag.
Cons: You need to log in to use driver! (Really, WTF!) Glossy finish. (Same as Das)
I hope I can give a better opinion after I get used to it more.