Similar story as mine.
I actually made it to Round 2 with the rentals actually.
Soon after that happened, I finally got my team transferred over and wrecked everything.
Dragon Rage kills the Pika Cup.
The big problem was the AI got to use higher level Pokemon and they all got great moves on them while the rentals got a bunch of crap moves.
Also back in gen 1, special attack and special defense were combined into the "Special" stat which made Amnesia one of the best moves in the game.
The announcer was definitely the best part of the game.
Imagine if he announced the smash games.
I'd pay good money for that.
My team (transferred from Blue) was
Felt some good fighting with my hard raised Pokemon compared to using rentals you have no attachment to.
Also Gym Leader Castle was incredible.