The Android OS 4.4 seems to me very well. It took me some time to adapt, but I can not say enough regarding the software: fluid, intuitive and complete, that is all I ask. There is, moreover, no overcoat from CAT, a definite plus. The "SwiftKey" is excellent, his "flow" function to write messages quickly, without lifting a finger (even though I had become an expert on physical keyboards T9!).
The pictures are of good quality, even if it was not me an absolutely necessary condition for the choice of smartphone. The flashlight, although less focused than the B2100 or B2710 that of, is powerful enough.
I was a little taken to reading the reviews here on Amazon, regarding former smartphone models CAT (B15 and B10), and, frankly, I do not see a single flaw that I could fault this B15Q. So yes, I'm still new at this, but this phone has, in my opinion, it all:-resistant IP67, Android 4.4, a nice design (subjective, I grant you) still square. In addition, with its 1GB of RAM, I never reaches saturation, the software is therefore still very fluid.
After comparing for weeks different brands (MTT, CAT, CrossCall, DracoTek, ...), this is where CAT B15Q that my choice was, and although it took me. I can only recommend it! It's expensive indeed. I myself have bought on amazon.de to 329 (much cheaper than Amazon.com, as always), delivered to Belgium in 2 days.
If you have any questions, feel free to ask me in the comments.