I've seen some people say it gets hot like the S4, but that's simply not my experience. Everyone has a different threshold to something like that, but I can honestly say it's not something I've noticed (which if I did, would mean it's getting hot, but I don't).
I've used it in my work truck, plugged in to power, using navigation and streaming Spotify at the same time, and still didn't notice it getting overly warm. Certainly not as warm as I've felt my S4 get with less strenuous use.
Hope that helps.