M2K's opinion is more valid than a random scrub pulled off the street.
Everyone's opinion is not equally valid. Experience and common sense are factored in as well. <<
Clearly. But you took a single one of my statements that didn't really have to do with the content of my post a little too literally.
What I meant is that just because I don't cpmpletely agree with him doesn't mean I think he is wrong in thinking what he thinks. He's entitled to his beliefs and they may very well be more right than mine.
Either way back to the matchup...
Lucario clearly beats Diddy in the killing and surviving department. I think Diddy wins in gimps though -- not to say he's going to be getting one really often, but his recovery gives him more options than Lucario's. Before you call me biased or whatever, (I use Lucario as one of my main characters also) think about it. Lucario has 3 options while recovering if forced to use his up b. Wall cling (not even all stages have this option), snap to the ledge, or go to the stage. Diddy can also try to go for the edge, over the stage, or the wall cling, but has a more versatile approach to it considering that he can snap to the ledge with 2 moves, go over with 1 and wall cling with 1 (that's 4 versus 3), not to mention edgehogging him is a little harder since his up b has a hitbox. He can also recover further.
I'm not saying his recovery is tons better, but I think it is better. He also has more projectiles to gimp with; peanuts, bananas (up to 2 at a time), whereas Lucario only has AS and that travels in a straight line so to gimp an opponent below the stage you have to jump off.
Both characters are good comboers. Lucario's fair leads into pretty much any of his other aerials depending on the location (if it's a SH you probably won't use uair). His jab combo has some nice mixups and his dtilt and throws are nice for combos at low %. After he gains some more damage, his comboing deteriorates but instead he just gains more power per move. Diddy I think is more ground combo oriented (he might finish the combo in the air, though), whereas Lucario combos more in the air.
Overall I think Diddy is better at racking up damage, but his damage racking abilities actually maximize Lucario's as well, since he will raise Lucario's % (and have trouble killing him).
I think on the ground Diddy is at an advantage, and in the air Lucario is. I guess the key is to stay aerial as much as possible and fight against Diddy's anti-air game (which is pretty good, but not as good as his ground on ground).
I think a good CP might actually be RC (though Diddy isn't awful on it, it's not an optimal stage for him, especially since you're forcing him into an aerial fight).
I'd say it's a fairly close match a little in Lucario's favor. 60-40ish.