Don't buy it yet. I'll try to be brief. I sold a dota 2 Item for 300$, so I had a fair amount of steam funny money to spend. I was a diehard call of duty 4 fan and played it competitively but most of the CoD games after sucked in comparison at least in terms of PC releases. Anyways it's no secret that the recent Cod releases the past couple years have just been rehashes of each other. So I had my reservations on getting AW. But I watched Total Biscuits review and the game looked like a ton of fun, so I went ahead and bought it with some of the spare funny money I have in my steam account.
It is fun. However, the multiplayer experience is ruined because they decided to go with peer to peer hosting. If you look at reddit.com/r/codaw you will see there are tons of people complaining about the lag. I'm on a 50 Mbit connection and play many games without lag and I've witnessed it myself. It's extremely frustrating, you run around a corner shoot a guy 3 times and instantly die, you then watch the kill cam and see from their perspective that you never fired at them and that they saw you earlier.
They absolutely need to patch the game to support dedicated servers. It's 2014 and a game made 7 years ago had a much better multiplayer experience. That's just sad. And it's clear by their design that they were aware of this, in Cod4 the game supported servers of 32 -64 players, CoD AW supports a maximum of 18 players.