Daydream experience
Yes, the Daydream gets warm, but I've used this thing repeatedly for more than 30 minutes and never encountered a device shut-down. It depends on how you use it. If it's for passive media consumption, the temperature generally doesn't go up as high as when you play games.
My biggest problem is that there's no VR browser and so for now at least you're limited to curated content made available by Google.