I have the same problem. My data connection will just stop at random and Facebook and Google now won't refresh, YouTube videos will suddenly stop playing, and upon hitting retry I'll get an error in both the playback screen and comments, and also the speedtest app won't finish preparing the test when I go to verify that my data connection is severed. I would have to restart in order to get data working again. I do get LTE speeds when it works, but it seems that the OPO takes longer to ramp up to those speeds compared to my Nexus 5 if that makes any sense?
Current Phone: OnePlus One 64GB, Nexus 5
Current Tablet: Nexus 7 (2013)
Previous Devices: Xperia Z1, Galaxy S3, Nexus 7, HTC One V, LG Optimus Elite, LG Optimus V