Why did you have to RMA your Nexus 4 , what was wrong with it ? They seem to be having quite a high RMA rate. I RMA'd my first one due to crap battery life and WiFi issues. My second one is fine now that I changed my WiFi router at home. But the N4 has definitely got dodgy WiFi chipset or drivers.. I had issues with 2 different Linksys routers even with multiple different firmwares DD-WRT, Stock etc.. No other device had any issues with these routers including my Nexus 7, Samsung Galaxy S3, HTC Desire, various laptops/notebooks. The 2nd Nexus 4 was the same fault as the first.
I agree the RMA process is very east and no problems getting Google to send you a new phone, but they are crap at admitting to the actual issue existing in the first place and dont seem to be able to offer any actual fixes other than factory reset, clear cache, re-add google account... They also blatantly lie about things..like "this is the first time this issue has ever been reported"...Intresting that a quick google search reveals hundreds of complaints about various WiFi Issues with the N4. There has been some offiicial confirmation that Qualcomm WiFi drivers are buggy..but no fix date has been provided..