I'm happy with it and I don't think I could go back to a membrane keyboard. I originally had some issues with the space bar colliding with the right alt key and getting stuck in the pressed position when using my right thumb. I solved the issue for the most part by re-seating the space bar and applying some White Lithium grease. For a detailed account of my issue you can see this thread. Black Widow key "collision"
Additionally, I cleaned the keyboard with some water/alcohol and it seems to have seeped into the lit-up Razer logo on the wrist rest and has removed some of the black leaving what appears to be bubbles. From time to time the logo flickers but a light tap on it solves the problem.
Other than a finicky space bar and some cosmetic annoyances I've enjoyed the tactile feel of the keyboard. The only other complaint I have is that the macro keys have proved pretty worthless to me. They're in an unnatural position and too clustered near crucial keys (e.g. ctrl, shift, etc). It took some time to avoid hitting these, but after a few days/weeks muscle memory prevailed. On another note, writing papers on this keyboard is wonderful and more often than not I have found that the flow of my writing has improved substantially. Furthermore, gaming with the keyboard has certainly been a step up from my cheap Logitech $30 membrane keyboard.