The earlier devices I updated with an unofficial Android are generally ok. Maybe for the old Huawei phone the newer Android version was a bit too much, it would sometimes struggle running it, but generally it worked. I think it was maybe related to the Huawei device having very little memory and internal storage, and maybe lack of CPU power. It was a cheapo low-end phone already when it came to the market originally (Huawei Ideos U8800).
The one I installed on my ASUS tablet (not Cyanogen, but some other, I don't recall the name) otherwise works fully fine... but Skype crashes upon launch on it every time. I don't know if it is related to that Android installation or Skype itself, but Skype works fine on other Android devices. Also I can't be sure if Skype would nowadays fail also on its original stock ROM.
All other apps (and games) seem to generally work fine on that tablet, but Skype doesn't. That's a rather big minus, similar as to many would be Facebook not working.