I have to say I am so very very let down !!!! I had to vote No.
The upgrade was a nightmare.....after upgrade my 640 XL was no longer able to be hard reset......holding the 2 button combo would just do an endless reboot loop it would not let me get to put the power cable in.....so I thought I would try to forge ahead....if anything had to be installed to the SD card transfer speed was now impared. To transfer files from PC to phone was like doing it via IR ( if any remember how slow that was back in the day).
Loading a game from SD.....not even possible 10 min to load candy crush saga.........now you may say the SD card is at fault......nope tested on PC to my built in card reader.......transfer speed as it should be, but to put anything to SD via sync cable from PC to Phone well slower then USB 1.
Even now as I am trying to roll back to 8.1 the software recover tool is having issue downloading.....almost an hour now to download (300 MB of 1.8 Gb ) my phones 8.1 software.....download is failing and failing.........
I am less impressed each day
!!!!!!!!!!!!!!