I successfully installed the 10166 build on my Lumia ICON and here are my thoughts and experiences with it...
After a straight upgrade, I encountered the pesky LOADING for the start screen...would take 2-3 minutes to bring up start screen and even then, after a few reboots, the screen wasn't very responsive. So started the CAMERA all so I could attempt to get into the settings, which it did let me and then I did a hard reset on the phone for a clean install of 10166 with NO RESTORE FROM BACKUP and set up as new phone. After that, things improved dramatically.
Everything seems to run quite well and for the most part, fast, on the Lumia ICON. I have encountered no show stoppers but here are a few things of note (and not all are specific to the ICON)
Outlook live tile doesn't seem to work.
Many live tile abilities of apps like Windows Central and NextGen reader don't seem to work. At least the "counter" on Windows Central isn't working for me.
Cortana doesn't seem to be my default text message/voice to text with my Uconnect in my Jeep. (and man, I miss it already)
The Photos app seems quirky. Sometimes doesn't immediately show recently taken pictures.
Device Hub is missing (and really needed for my DT-903 charging pad so I can adjust the "light" times...
Wireless charging with the DT-903 deems to be at a snails pace.
Batter life seems a little worse. A "little"...
Podcast App still crashes (closes) as much as it did on 8.1.
Zedge will not save ringtones.
Overall, I would say this is good enough for a daily driver as long as you can continue to grow with it.
After a straight upgrade, I encountered the pesky LOADING for the start screen...would take 2-3 minutes to bring up start screen and even then, after a few reboots, the screen wasn't very responsive. So started the CAMERA all so I could attempt to get into the settings, which it did let me and then I did a hard reset on the phone for a clean install of 10166 with NO RESTORE FROM BACKUP and set up as new phone. After that, things improved dramatically.
Everything seems to run quite well and for the most part, fast, on the Lumia ICON. I have encountered no show stoppers but here are a few things of note (and not all are specific to the ICON)
Outlook live tile doesn't seem to work.
Many live tile abilities of apps like Windows Central and NextGen reader don't seem to work. At least the "counter" on Windows Central isn't working for me.
Cortana doesn't seem to be my default text message/voice to text with my Uconnect in my Jeep. (and man, I miss it already)
The Photos app seems quirky. Sometimes doesn't immediately show recently taken pictures.
Device Hub is missing (and really needed for my DT-903 charging pad so I can adjust the "light" times...
Wireless charging with the DT-903 deems to be at a snails pace.
Batter life seems a little worse. A "little"...
Podcast App still crashes (closes) as much as it did on 8.1.
Zedge will not save ringtones.
Overall, I would say this is good enough for a daily driver as long as you can continue to grow with it.