If you're wondering whether or not you should get this version as opposed to the normal version, you should get this, because it contains the following things which you'd usually have to get as DLC, in the complete edition you get:
-Core game (meaning, the game itself)
-Map Expansion
-Premium Upgrade
-Vehicle Pack #1
Vehicle Pack #2
-Police Car Pack
-More Licensed Music
-New Vinyl Pack
So, for about £10 worth of your money, you get a lot of stuff.
The game itself, if you've played Midnight Club 3, this game basically follows suit, you get to race cars that you can modify to go insanely fast in order to progress through the career and earn rep, thus unlocking more cars that can be made to go faster. A new thing (I think) in this game is that the races are colour-coded, from green to red, green being easy and red being hard, that way, you wont jump into a race only to discover your car is pants compared to the opponents, meaning that the game ushers you in fairly easily, without upping the difficulty to quickly.
As far as races go, they're fun, at the starting line, the opponent will make an attempt at insulting you, to which your character responds with a funny comeback, which in all honesty is better than what you get out of most games nowadays, especially when you proceed to pummel that smug opponent in the race. Also, during the races the opponents will randomly say things, which is kinda funny but they repeat stuff a lot.
Now for my main problem, traffic, now I appreciate that there is probably a lot of traffic in Los Angeles but it is SO dense that when you're going at 150MPH+, laughing at how far behind the opponents are and then suddenly out of nowhere a lorry turns and you smash into it, creating a rather substantial pile up and slowing you considerably, it isnt funny, couple that with the sometimes loose steering of cars and you get a recipe for disaster.
The police chases are pretty good, but they seem to be able to keep up with you suspiciously well considering they're using standard Police vehicles, but apart from that it is well implemented.
In summary, for the money you can't go wrong with the complete edition, it's fun, challenging and funny