The Nexus 4 is known to have overheating issues that naturally throttles it (The LG Nexus 4 lacks a proper heat sink, causing overheating and throttling - Pocketables), and I've noticed it decreases my battery life as well. It also has known data connection issues (Google Groups).
I have both issues, and the latter is the worst. I have never experienced it until recently, but let's just say that my Nexus 4 is never in connection.
I have been a Nexus 4 user since early December, and this is my second unit that I am on (my first Nexus 4 had all the issues that the first batch Nexus 4 had). The Nexus 4 is a wonderful phone, but it does still have it issues. With that said, I still think it is the third best phone in the market (First: HTC One, Second: Galaxy S4).
Well I don't know anything about overheating and throttling of the N4, but I do know that it stays in my pocket about 95% of a week, all day at work and with keys, and degrees of about 60-85 degrees daily. Battery last all day. By the time I get home I still have about 70% battery and don't need to charge it, but I do JOGP. So, don't be scared of what issues some may have. BTW,... We have 2 N4s and both are just great.
PS... From 2 windows 6 phones 2007 - 2010, to 2 N1s android phones 2010 - 2013, to now 2 N4s android phones, and considering 2 N5s android phones. If not 2 N5s, then the 2 N6s, or 2 N7s.