Johnzot,
I'm sorry to see you go. I'm a loyal Icon user, as well, and am also quite disappointed that none of the newer phones work on Verizon. I have an iPad mini (not my own, but belongs to a non-profit that I am a part of), and I find it clunky as well. I have tried Cortana on it, and find it rather... odd. The UI is way oversized, as if it was written for the phone, and is just stretched out over the larger screen. I have to admit, I've only tried it a couple times, and each time I've launched it, I've quickly closed it and went straight for Bing. I must be doing something wrong, but I don't use the iPad often enough to bother trying to learn much about it. It was bought mainly for the ability to use Square, which is the only app I've ever found myself desiring that isn't on Windows. If they'd have a Windows app - even a Windows x86 desktop app - I wouldn't have bothered spending the money on the iPad.
I, too am watching for the next Windows phone to hit Verizon, but if it doesn't, I'll hang onto my Icon until it dies (there is nothing lacking right now), and when that happens, I'll buy another Icon - somehow. Oh - I'm not seeing the battery problem you've described, either, but I'm not using What'sApp, either.