I'm not fussed. My pokemon are still at the level 20 cap and battling Brawly will push them over that for sure - Don't forget the area from Slateport to Mauville is quite large with the beach front, the Team Aqua/Magma stuff in Slateport, the Trick house and the trainers to the left and then going underneath Cycling road - there's a good chance you might push over level 25 before the third gym! Just a heads up so we can try avoid cooking the levels on our Pokemon we use in battle too much
In saying this, my Pokemon as I said are still level 20 so anyone who wants to battle, I'm available and I won't fight Brawly till later or when I've battled whoever wants to :)