Umm.....
1. M2K is more aggressive in practically every way, including grabs.
2. If you don't think M2K combos, then you must've been watching a diff M2K.
3. M2K is better against spacies, and dittos, and probably every matchup, character-wise. Ken still has the experience factor.
4. M2K doesn't use mind games AS MUCH AS pure flawless technique. The main asset to any smasher IMO has always been move placement; knowing which move to use and when exactly to use it. He's been spending the past year(s) studying every angle/option of the game, and it's paid off. I give him mad props and respect for his accomplishment.
I'm not saying M2K's better, but I would say that he's pretty justifiably the best Marth right now, and from watching him grow and his play style change over the past 3 years, I'd say he's on his way to becoming the undisputed top dog in a very short period of time. Wait till the OC3 vids come out, and I'm pretty sure you'll agree...