Legends of Wrestlemania is by no means a bad game.
One of the selling points of the game was the simplistic control scheme. It isn't really that bad once you get use to it (and to be honest, I felt that they were leaning towards a control scheme similar to WWF No Mercy with the whole weak/strong grapple thing going on), but my biggest hang-up about it is trying to do reversals. Sure, it is understandable that you have to pull the stick away and hit Y to reverse, but if the camera is fixed and doesn't move (mostly in cage and triple threat matches), it can be an annoyance to try and escape a grapple or block a strike, since you can't simply move the analog stick left and hit Y at anytime to reverse a move.
Another selling point was the Relive, Rewrite, and Redefine modes. Relive Mode does a good job in trying to recreate some of the moments that it presents by having you do objectives that replicates key moments in the matches it provides, such as having Stone Cold drop an elbow on The Rock on the announcer's table in Wrestlemania XV. But when you get to the Rewrite and Redefine Modes, those objectives become generic, such as simply performing a taunt or doing a strong grapple. At least each match provides a video montage of said match, and it is a nice touch that you can unlock more video clips of other feuds as you progress.
Roster-wise, Legends of Wrestlemania has a solid offering of wrestlers. It does suck that other legends like Randy Savage or Ricky Steamboat didn't make the cut, which I'm sure there were solid reasons as to why. But the ability to import the Smackdown vs. Raw 2009 roster is a nice feature to at least increase the number of wrestlers in the game.
Overall, Legends of Wrestlemania is a decent game, and it is worth a rental. It might not be as great as Smackdown vs. Raw, but it is still a fun wrestling game.