I had O but was waiting on Q as I didn't want to side load. Downloaded U last night. Haven't tested it out but will tell you the zero bars issue is gone. I get slightly better signal at work.
At home at my highest I was at about -110-112 dbm. As of now I am at about -105dbm at home. Not super great but if I can hang onto a signal without Wi-Fi calling I'll take it
*Update* My signal seems to even be improving a little more from last night. For the past 3 hours I have been home from work it is hovering between -97dBm and -100dBm and is pretty steady between those numbers. I have never seen that on this phone for me