So I don't know if anybody has tried the Big Surf Island DLC for this, but I finally got around to picking it up. Man, what fun! It's really quite small, initially almost alarmingly so, until you realize you have more opportunities to go offroad and it's also built rather vertically, with lots of stuff you can sort of climb and then fly off of and such. Parking garages and the like. It feels quite a bit more open and fluid than the stock game, which is nice, and it meshes very well with the rest of it. Comes with a free car which is a fun stunt-focused dune buggy, and you get a new license while on "vacation" when you drive over the bridge to the new content. It's got new jumps, new smashthroughs, new billboards to break, I think 8 cars to unlock, and of course a number of events. Your mileage will certainly vary depending on how you play this game, as there isn't a metric crapton of new content, but I spent several hours yesterday just tooling around and having fun trying new things and seeing what I could find, doing a few races, etc., and I'm nowhere near "done" with it. It's definitely worth twelve bucks if you liked what the first game offers. It also helps that it's a bit more extreme, so it ups the ante as far as some of the big jumps and stuff go (they call them "mega jumps" rather than super jumps, heh).
Definitely a good time. Check it out if you've not done so.