I also have the OnePlus. Prior to the OnePlus, I had the Nexus 5. I don't remember reception on the Nexus 5 so sorry, I can't give a great comparison. However, this morning, I noticed an area that was typically a dead zone on my commute, I had a strong LTE signal with the N4.
Sitting in my office, my WiFi is noticeably weaker than on the OnePlus. The WiFi keeps dropping which was never a problem with the OnePlus.
I installed Google Wallet and everything seems to be working normally. I haven't actually used it yet with the N4, but it installed without any issues.