Come on folks, saying boot time doesn't matter is like saying load times don't matter. Technology is progressive, and will only become more convenient. Thus, some will complain, and rightfully so.
Like some have pointed out, some will cold boot while some will not. Therefore, this will only affect those who cold boot for whatever reason. As for the time itself, it does seem a little long. My PC boots in less than 10 seconds with an SSD, and it used to boot in less than 30 seconds before the SSD. My laptop with a 5400rpm hard disk and Win8.1 boots in roughly 30 seconds as well. So, Xbox One does look a little slow.
I'd imagine it's probably early stages of it's complex OS built on 3 OSs' so it should get better through system updates over time.
As for the heat, it does seem a little disappointing considering it has the power brick outside and a bigger heat sink (with a weaker APU) compared to PS4; not to mention the bigger housing.
e=mc^2
Gaming on: PS4 Pro, Switch, SNES Mini, Wii U, PC (i5-7400, GTX 1060)