TL;DR: upgraded my x150e yesterday via the Upgrade Advisor app.
Been following this thread with interest since the beginning, I bought my phone from Amazon UK in November 2015 when they were selling them for GBP50. Wasn't that desperate to try W10 to jump through the hoops described in the thread and was happy to wait until the official route eventually became available. Another factor was that I quite like Here Drive as a sat nav app and after their recent announcements about dropping the app from W10 it was another reason to wait.
When the Upgrade Advisor app first became available I was - no doubt like many others - checking it on a daily basis. That quickly became pretty boring and I hadn't check for two or three weeks when I was on the way home from work on Friday night when I checked again and it said it was available.
Long story short - went through various downloads and updates, required a hard reset at one point to free up enough space for the update and I eventually ended up with a working phone. At this point I ended up with what I thought was a bug and did another hard reset to see if it fixed it.
In Outlook Mail I had two accounts set up - one work and one personal. However there was no way to swap between them. The left hand vertical menu did not appear, nor the hamburger menu nor the three dots in the bottom right corner. I knew it was 'seeing' both accounts as sending a new email to my personal account made it appear on the live tile, I just couldn't access the account (or any other folder in my work account).
On reflection I think the bug is to do with Outlook Mail and setting the 'size of text, apps and items on the display' to 200% - I think this caused the outer areas of Outlook Mail to be hidden from view. Anyway, it's all running OK now on std text size.
Hope that helps.
Mod Note: Removed pic with partial IMEI and MAC Address.
Version: 1511
OS Build: 10.0.10586.420