Yeah, I went back to a previous build as well. My plan is to test doing a complete wipe and setting up the newest build from scratch, but need to find the time to do it first.
Haven't seen a single post on this forum or elsewhere of someone who had trouble with this latest 7968 firmware build who was somehow able to fix and/or pinpoint why it slows down or drops out. All who have had trouble have resorted to a fallback build, generally 6436.