Wow, I honestly think they're much, much more better.
Going though most sagas to viewing pleasure has also, in my opinion, gotten better - introducing more animation into attacks and such.
>But on the topic of battles. I have to admit, were VERY poor. We had such battles like Ash Vs. Ritchie, which in my opinion - neither of the two should have been able to get that far into the league and get 8 badges with still such poor pokémon Ritchie had, like Pikachu, Charmander and Butterfree, plus Ashs Charizard just feel asleep and Ash lost. xD
I honestly see the battles in Pokémon more intense and strategic in the newer series. Take a few battles like Ash and Paul and Ash and whatshisnameiforgotwithadarkraiandlatios much, much more intense battles, real nail bitin' stuff. xD
But considering yours already comparing battles in Best Wishes to battles like in the first movie. @.@ I don't think Ash would be able to take on a Pokémon with power equal to Mewtwo with only three badges.
On the other hand if you would compare Best Wishes to the Original series, lets compare some of the earlier battles. In the original series, in about what? The fourth episode, we had Metapod vs. Metapod - really intense stuff there, am I right? And then in Best Wishes, we have battles such as Ash's battle with Trip, Snivy Vs. Pikachu, which in my opinion - much better battle than Metapod vs. Metapod, we had Pikachu - take on trips Snivy, but without the ability to use electric attacks, Pikachu lost - but during the battle I can say I felt like screaming at the scream thinking, man hes seriously not gonna lose to a simple rookie snivy. :P
So yeah, ima be a little controversial n' say that I disagree.