If I had unlimited time on my hands, I'd probably watch both Build and LPs. But I don't, so I rather spend those hours playing or organizing my own game. I do watch some YT vids though, but mostly Machinima (like real movies where roles are played by sims), because i make some of those myself.
Watching Build/Play might give ppl new ideas, learning how to use misc features, or simply pick up some inspiration to play their own game. I'd think that if seen 10 build vids, it would feel a bit repetitive, but I'm probably wrong :)
