I've been wondering about that same driver. They were on sale at PE in the summer, but I choked and didn't order any. The only concern I have is the Fs=46Hz and if you want deep lows it might not be the best choice. I've used other larger Eminence drivers with Fs in the 40s with great results, but I wasn't going for low response, just punch and they delivered that with boots on! Notice the Xmax is 3.2mm, but the mechanical limit is 21.84mm. It's designed to shrug off abuse and you will definitely get some punch out of this bad boy.
Quote:......... does that sensitivity stay greater throughtout the power curve?
There's an evil warrior from the dark side called power compression that plays havoc with the math of designing a sound system. I can't remember exactly how to figure it, but it has to do with motor strength and compliance, but also the type of cabinet you use and Xmax of the driver affects compression to some degree.
This looks to me like a driver that can hold up fairly well against those evils and you should reach the Xmax without any compression. Some of the ridiculous Xmax specs you see will start to compress (meaning double the power, you don't actually get 3dB gain, yuck) well before half the Xmax is reached.
So, I guess the question is: Do you want digestion halting low response or bone rattling punch out of your build?