I actually enjoyed Mace Griffin quite a bit but it's not for everyone. A few missions have timed sequences where you must make it through a level (that you've never seen before) with a bunch of dead-end paths, while taking sniper fire in the ass before the clock runs out. Those parts of the game are purely trial and error and somewhat infuriating, but there is still a lot to like about the game. The weapons are pretty cool and they all have alternate fire capabilities. The running and gunning action is well done and there are plenty of sniper opportunities. The integration of on-foot missions with spaceship dogfighting is amazing, and having to chase someone on-foot then jump into your ship and continue to chase them out into space is a very unique dynamic. I've heard some complaints about the spaceship controls, but they're fine once you get used to them.
But make no mistake about it, this game is NOT EASY and certain missions demand almost perfect execution to complete them. Overall though, it's got a great Han Solo kinda feel to it, and if you've got the patience to get in to it (and can find it cheap) I'd say go for it. You may just be surprised.
(XBOX version only... PS2 version is nowhere near as solid)