KF1 (Cognition 5v2) is my daily as well. I have a slightly longer list of issues, but they don't happen often.
-I removed my EXT SD card due to the app install location problem. The whole phone seems to run better when it is not there.
-Abnormal battery drain for CELL STANDBY. This happens on occasion, Reboot seems to solve it for a while. Pretty sure it is due to low signal where I work, which is always an issue to work-around.
-Random shutdown. This is rare, and when it does happen, is typically when I plug in to charge, so not a huge problem. If it happened more, it would be.
And that is it. Runs very fast on the EXT4 in the Cog kernel, and everything else works great. No BT issues, good voice quality, dock sound is great and the battery life is at least as good as the best I have ever had.
I am closely watching the KH3 builds, and will likely try one shortly now that they have been out for a bit and others have found the big bugs

.
CM7 for our phone raises the bar quite high, and unless you snap a lot of photos or just have to have audience chip (voice quality) support, it may be the best option.