I did a factory reset to clean out old files. I spent this afternoon putting in passwords, etc. The first thing I noticed is that iSyncr no longer works when I tried to add my music. I use a Mac , and HTC Manager has always froze up my mouse since the Mavericks OS came out so it's not an option. I tried Android File transfer and no luck recognizing the phone. It may be a Mac issue and I don't blame AT&T. I'm working with the folks at iSyncr to get it working again tomorrow. Doubletwist may be my last option for getting my playlist on the phone from a MacBook.
Other than adding Music (with a Mac) , I'm happy so far with Kit Kat. Blinkfeed is definitely better with 5.5 version.