So far, aside from the graphics load, the only downside to this game that I've experienced is that it takes a bit of time to get used to. The gameplay is rather complex, which is cool because it means you can do so many things. You're no longer restricted to just 3 or 4 actions.
Plus, having fully-fledged tanks, realistically designed and implemented, with full tank crews (commander, driver, gunner), is something that is really awesome.
It's really very dynamic.
What's also cool is that it comes with its own bots, and a practice mode, which allows you to play and gain experience with the features, weapons, vehicles, and environments, before you jump into the online battlefield. Which is invaluable, since like I said before, the game can be tough due to all the features and the broad spectrum of actions and possibilities.
The other great thing is that the game utilizes the setup configuration characteristic of Unreal Tech games, which gives you a broad spectrum of configuration options for the video and audio output. So even if you have just a moderate machine, you can still play by tweaking things down a few steps.