I got my 950XL yesterday which replaced my tired, "pre-Denim" (thanks AT&T :angry
Lumia 920, and after playing with the phone for over 12 hours, I am a very happy camper!
Having waited a month to get the phone, I watched or read just about every review I could find. If one bases their opinion of the phone on what the reviewers say, you'd think this phone was a complete fail. There seems to be strong anti-Microsoft bias in Internet-land these day, even among Microsoft fans.
I'm happy to report that I haven't experienced any issues I've been reading about so far and I absolutely love the phone. I'm having no issues with getting LTE service, the Glance features all work like they used to on my 920, and I finally have a phone that is running Windows 10 just like my laptop and tablet are. I think it's very cool that my phone, my PC, and my tablet now all have the same look-and-feel.
To me, the only real issue with the 950 XL, or Windows Phone in general, is that the "app-gap" is very real. However, as a Microsoft .NET developer by trade, I am seeing signs of hope that some headway is going to be made in resolving the app-gap in the not-so-distant future. Just about every developer I've met that's used Visual Studio loves it (yeah, even the Java guys love it), and now iOS and Android developers can use it. In addition, UWP (Universal Windows Platform) makes it considerably easier for a developer to make one application that will work on all Windows 10 devices. I think that's
huge because Windows PC's are still in the majority and so it now makes a little more sense for someone to develop a Windows 10 app because it can have a much larger audience than just a few Windows phones.
The app-gap certainly isn't going to close over night, but in the mean time, I think the 950 XL is a truly great "enthusiasts phone" and hopefully a stepping stone towards a bright mobile future for Microsoft.