I have found the pi 3 to be awesome to use. I bought my first one 3-4 weeks ago. I loaded retropie, a rom and I have a dedicated galaxian machine. I had to do some reading on how to make it boot silently, that is no boot up text graphics etc. That's the part that has always annoyed me about using a pc, getting rid of the bios bootscreen is difficult and then hiding windows can be a pain depending on the version.
I have a pi image backed up, so to make a new game I just change the rom and a line of text and good to go. It boots straight into the rom in about 20 secs.
The on off issue hasn't been a problem for me. I just switch it on and off at the power switch at the wall.