Positive, from time to time funny, interesting theme (explains/shows a bit how anime are created, constraints, etc...), very precise graphics, sometimes for me very fast sequences (had often to go back a few seconds to be able to read the subtitles and/or watch better a few seconds of some nice animated scenes). Unluckily I didn't like the final anime that they created, hehe... .
I didn't regret watching it, I might watch it again in the future.