His stats, if I am not mistaken, are exactly the same as in Melee. The differences you are experiencing are most likely due to the difference in game mechanics (leftover Brawl schtuff) from Project M. To me he seems better. His Dancing Blade connects much better than it does in Melee. He now has a pivot grab with RIDICULOUS range (as my friend described it, it's like a tether grab with none of the weaknesses lol). And due to some leftover Brawl mechanics, he now has a DACUS, which, while frame perfect and very situational in the case of Marth's Up Smash, can be very handy to catch your opponent off guard, or to quickly cover a bit of distance, or as a generally nice mix-up... If you're really good with it (and your opponent DI's incorrectly) you can even combo into it for an early Up Smash kill... How often do you ever get an Up Smash KO in Melee? Never. Wave Bounce or B-Reversal... whatever it's actually called... All of these things, at least in my opinion, serve as buffs for Marth and more than make up for the slightly unfavorable changes from his Melee incarnation.
If you don't know about some of these techniques... LEARN 'EM! They are ever so useful.