I bought these heads for a very specific project I was working on. The fact that they look super cool is just a happy and welcome bonus. They offer a very fat, wet sound on toms that can give you great scope for exploring different recording techniques. Or if you just want to get a wet sounding head with loads of low end presence and just about enough punch to get by. It certainly won't be to everyone's taste but it's a very interesting sound, worth exploring. As an additional bonus they are extraordinarily easy to tune, and (as long as you're not a really heavy hitter) to keep in tune.
Evans Hydraulic Blue looks different and beautiful. When you put blue heads on all drums make you feel different. This heads are for loud drummer only. If you have to play quietly this is not for you. Sounds good when you push harder. Short sustain, but enough. For rock and heavy music.