I have had my 950 XL for a little over a week. I have primarily used Android devices over the past few years, with the Note 5 being my current device. I tried a 635 a while back, got if for like $25 on Amazon, and totally loved it. In fact, I ended up using that as my primary phone over the Moto X Pure Edition I had at the time. Since then I have used a Lumia 640 XL, and that also fantastic. When the 950 XL came out, I was pretty sure I wanted it. The first one I got was horrible, with extremely loud creaking (as in just picking it up would give off a horribly loud creak), so I got that replaced, but I still had issues with a lot of bugs, and general instability, so I returned it.
I decided to try again, so I bought a dual sim variant from B&H, and took the .29 update. The update has drastically improved the stability of the device. I am quite happy with it. There are still some issues, like the camera being unable to focus automatically under low light (works if I tap to focus). Sometimes my settings screen will freeze, etc. Windows hello sometimes doesn't work ( I have glasses though). Some annoying issues, but overall, not nearly as bad as the first one I had. I expect things will improve further with the new firmware update.
When everything is working, things are about as fluid as my Note 5, which is good. It doesn't load apps quite as fast as the Note 5, but then again, the Note uses UFS, so that is to be expected.
The camera on this thing is fantastic! Slower than my Note 5, but the resulting pictures usually have better detail. Quite happy with it! I would say it goes toe to toe with the Nexus 6P.
However, I still love Android and will keep the Note 5 around, so that I can switch back and forth as I wish.
Overall, the 950 XL is a pretty decent phone. It doesn't feel as good in the hand, or "premium" like my Note 5, or the 6P I used to have. I am a bit disappointed by that. I thought even though it was plastic, it would have a solid build with a soft touch feel like the Nexus 5X, but unfortunately it does not. The back still creaks in multiple places, and the phone is a bit lighter than I would like. It just doesn't feel like I am holding a solid phone in my hand, like the Nexus 6P or the Note 5. I suppose I could add some post it notes or something for the creaking, but for $650, I expected better. I have a Mozo cover on the way though, so hopefully that makes it a bit better and maybe even gives it a bit more heft.
Again, with the new updates and the probably the new firmware coming out, I think this will be a very good phone. Hopefully the whole Universal Apps thing takes off well.
Haven't tried continuum yet, don't see the point when I have my desktop I built last year

It wouldn't support my Dell's resolution anyways.