So I went into the MS store last night (in Woodland Hills, California) and they had the 950 XL on display and available for demo. One of the phones had a really hideous case on it. Can't wait for the Mozo back covers to start showing up. They did have one untethered 950XL to play with. It had the white cover on the back. That phone was running Win10 Build 10546. It was pretty fast phone and I encountered zero Loading or Resuming. I opened about 17 apps in quick succession and toggled back and forth between them and not once did I encounter the dreaded Loading or Resuming screens. This thing is fast, it has 3GB of RAM and it shows!
The phone felt extremely light in the hand and quite easy to hold. It is a big device but the overall device size isn't too bad, the top and bottom bezels are quite small. The quality of the screen is top notch! I did remove the back cover and the battery and checked out the internals. Everything feels solid, the tactile feel on the buttons was really nice. Windows Hello was not demonstrated because it was assigned to one salesperson in the store and he was not on shift when I visited the store. The white matte cover is nice, especially when compared to the glossy white covers for the 640 and 640XL that they also had on display. I cannot comment on the battery life in the short time I had to play with it.
I played a video on You Tube and the audio is stellar on this device. Very impressed, despite the speaker on the back and if you put the phone face up the sound is likely to be muffled but if it is placed face down the audio quality is very nice. I played with the rear camera quite a bit. Snapped about 10 pictures with and without flash and I must say the picture quality is superb. The time to load the app is very minimal and it locks on to focus very quickly and I tapped 5 pics in quick succession like on my DSLR and there was no lag on the device! I tried out the FFC and even in a non optimal light setting environment it took really nice selfies. Also took a video and the HAAC mics picked up the complete din in the store and the mall. The video quality was very good and I did not detect a lot of jitter.
I tried Hey Cortana on it and it worked but because the store was quite loud I had to put the phone closer to my face and say Hey Cortana to the mic near the bottom of the phone - regular phone conversation microphone. You will see the two SIM card signs on the top since the phone had dual SIM slots, even if you only put one SIM card in it. In the time I played with it I did not feel the phone heat up or warm up at all FWIW.
All in all it is a solid device. Once Win10M is complete it will be interesting to see how this phone stacks up against the other big boys but a very solid first impression. They were accepting pre-orders at the store and I ordered one for myself.
But there's "one more thing":
You can also pre-order the 950 at the MS Store!! They have the SKU's for it. I have a picture of the exact SKU for the 950 which Jamie (the rep) scanned but was asked not to post it. So being a WP sucker, I pre-ordered that one as well. She said I can change my mind and decide to just buy one from the two devices but at least now I had the option of locking both of them in
Enjoy the pics!