All phones heat up... Use a phone case... You won't feel heat.
In my opinion, Nexus 4 is a lot superior to Xperia SP, and even Xperia ZR... Excellent value for money...
umm recommending a phone case to counter heating is bad. The biggest drawback of a phone case is that it doesnt allow heat to escape. Sure it will leave ur fingers cooler but think of the wear and tear on the chipset and the battery. My old Galaxy Ace battery swelled up like crazy due to overheating.
If battery and storage is not an issue then Nexus 4 is a great deal. Kit kat after all.... For me, i wanted a phone where i can pack lots of HD movies and games and not worry about phone dying off mid day, and that made me go for Xperia SP. It doesnt run as hot as Nexus 4 (due to plastic back) and i manage 30 mins of Nfs Most Wanted with 8% battery drain. Great job Sony on this one
I have also watched 3 (hollywood 1:30hr approx) movies in my hostel with 30% battery left !! Something i doubt a Nexus 4 can manage.
When people are playing games on my phone i dont have to say "oye battery khatam ho raha he yaar.." and stuffs like that. In fact i show them all the latest HD games and new videos i have downloaded...
Camera wise, i havent heard praises about N4 cam, but im not impressed by Xperia Sp's either. I uploaded shots on the Xperia thread and as you can see, too much color saturation. Its like the world has gone AMOLED
If you are a heavy user, like constantly downloading songs and youtbe videos on 3G and your phone is always being used by you and your friends for gaming and watching Dota replays videos
and stuffs, SP will be a better deal. If you keep the phone to yourself most of the time, Nexus 4 for you! Its lighter (hate Xperia SP's weight)and the gorgeous glass back may be your thingie.
Just giving my opinion
Plz no hate