Pros:
-Less Ken Block. In DiRT 2 he was literally all over the game and was the superstar in almost all forms of racing always coming first. In this game, his name rarely pops up in anything other than Gymkhana.
-More Rally. Though there is buggies, trucks and Gymkhana, rally makes up for about 60% of the game.
-Better Soundtrack. I hated the last one, it was pretty much all indie crap with only one song by The Prodigy. This one has a bit more rock and some dance/electronic thrown. I also liked that some Run DMC is in there.
-Dirt/Snow Buildup. Self explanatory really, I like how the dirt/snow builds up on the cars over the course of a race.
-Night Racing. This is where it gets fun, you literally can't see anything other than the beam of your headlights and your tail lights.
-Blow-off Valves. Besides liking the noise of a BOV, one thing I noticed in DiRT 3 is that they all sound different, I thought that was a neat little touch.
-Online. Party modes are fun, but that's all I've really played. The rest is the typical online you expect.
Cons:
-Inconsistent Difficulty. Sometimes I'll win races by 10 seconds, others I'll have a hard time reaching the podium and that's with the difficulty set to 2 of 6.
-Monster Energy/DC Shoes. The branding is everywhere, don't get me wrong I love Monster, but the brand placement is too much. As far as I know both companies don't have much appearance in real world rallying other than Ken Block on the Monster WRT, where he's sponsored by them and DC Shoes.
-Car Liveries. Probably a result from my last point, but the brand names try glorifying rally even though it doesn't need it. Even though classic cars like the RS200 are in it, expect to see it plastered in Monster, Rockstar or DC Shoes paint jobs. Like the classic 90's Scooby? You won't find the paint job to match.
-Commentators. They are annoying and you can't turn them off.
-Replays. You can't save them, other than the 30 second YouTube upload feature which didn't work for me.
-Tires. I lose them a little too often...
-Snow Grip. The car never goes out of control, it handles too well for my liking. I was looking forward to the cars sliding all over the place.
-No Playlist. I can't see what song is playing or turn off the songs I hate, like the song from Young Guns. Bad enough I had to see them live, I don't want them tainting my games.