Holy crap, this episode was way better than I'd expected! I already knew the battle would be fun to watch (not this good though, especially loved Gengar and Electrode in this) but I didn't expect the callbacks! Ash even mentioning that he beat Surge was a pleasant surprise for me; for the Gym Trainers to recognize him (cuz Surge apparently keeps telling 'em about the legendary Pikachu that took down his Raichu) and even having Ash use the same tactic he used to beat Raichu's electric attack, and then showing us that the Gym Trainers knew exactly what that tactic was...
Man, that's a ton of unexpected continuity!
btw one more thing I keep seeing in comments on this post...sure, Go's not really acting like a great trainer right now. But it doesn't mean he's a horrible person; it's just more proof that despite his Pokédex-level knowledge of every Pokémon out there, he's still a newbie trainer who doesn't really know much aside from throwing a Pokéball and maybe telling his 'mons to use the occasional move. He has space to grow more, sure...but he can, and will, grow as a trainer, just like Ash and all his travel companions have grown ever since the series has started.