I'd much rather like to see Ash get stomped and then after some practice come back with new moves (also known as character development) and win, rather then win on his first try. :|
On the episode itself, it was okay. I'm much more excited about the the rematch, though. I liked Mijumaru's mood swings, really shows that Pokémon are living beings as well, and not just some creatures stuffed into balls. And I wish we got more out of the entire library puzzle, but I guess we're lucky enough that we got to see the secret passage.
Oh and, I had no problems with the switch-outs. It's most likely one of the new gym rules in Isshu region.