I am not. I use an Xarmor U9BL-S which the blackwidow ultimate is very similar to. Just giving you more options that have similar features at a similar price point. I have seen some reviews on different sites which think it is a decent piece of hardware, but one drawback is some of the keys are not mechanical like the G keys I believe. Not sure how big of a drawback that is if you don't even plan to use those much, but the majority are mechanical. I also know that Corsair has well regarded customer support, so if something goes wrong, I would probably rather deal with Corsair than Razer.
Do you need additional keys than the standard ones and is backlighting a must? There are some decent newer ones that are a bit cheaper though they lack some of the features that I just mentioned.