Using the Electrix Warp Factory will certainly take a bit of practice, as this isn't your typical effect. However, after playing with it for a little while I felt that I could get the hang of it pretty well. There is definitely a good amount control over your tone, with control over both the mic preamp gain and for 'warping' your signal. The warp section has parameters for gender, Q (bandwidth), order, pitch, robot punch, effect mix, and a slew of buttons as well including for format freeze. If you are are new to vocoding, I'd definitely suggest having the manual around.
Even though I haven't used all that many different hardware vocoders, the Electrix Warp Factory is definitely up there with the best of them that I have used. It offers up a ton of control, and in general the tones sound clear and of course vocoded! You can absolutely make your voice sound like a robot with this box! It is quite powerful, especially because it has so many different parameters to work with. You can actually use it with any instrument, not just a voice, which is cool, but of course the best use with the Electrix Warp Factory will always be with a voice as this is what it is designed for...
I don't really know what kind of price the Electrix Warp Factory commands, as I don't own one and have never needed to do the research on it. However, Electrix usually has pretty good prices for their gear while still maintaining a very high quality. The bottom line with the Warp Factory is that if you are looking for a vocoder in a piece of outboard gear, definitely do not decide on one until you check out this one!