I have two, and the only problem I've had is the trigger spring breaking in one; which causes the super-sensitive button issue you are experiencing. Really easy fix though, I was able to do it with a basic online guide/video and just bought some extra springs for it.
I've had both controllers since day 1 of the console release. Used 'em heavily. Had a lot more troubles with Switch joycons.
http://tinyurl.com/b95dwtg