Bowser is better and my mind wont be changed. He is the more heavier character, he has has suicide move, his U-air is great for killing, his F-Smash is better in terms of damage. Also, Gimpy showed that Bowser is a force to be reckoned with, and I'll be guided by his Bowser.
Bowser has his disjointed A attack which cancels out some projectiles, such as Samus' Missiles.
It dont matter if Bowser is slower, it just makes him more like a Tank.
Bowser's F-air is perhaps one of the better moves that Bowser has, and he does have an Infinite Jump, making him more trickier in the right hands and is great for Mindgames.
Bowser's Up-B, perhaps one of the best moves I know in the game... Fortress outta shield is FTW.
Many ppl doubt the Bowser Bomb, but it is good when you use it at the right time, and for me, it helped me set up a great KO, from Bowser Bombing an opponent while i fall to grab the ledge quickly, jump up from the ledge and do a U-air to finish off the opponent quickly.
That's what makes Bowser better.