I get all the tower defence action I need from my iPhone
MAG is great fun, had another little blast last night (servers only running at certain times at the mo), standard controls with some nice upgrade options on things so you can come out in any style of fighting you want. I've mainly focused on sniping which at the moment at least is working out well as lots are going for the run and gun style so I have some targets, and get sniped back often enough to keep me on my toes and moving
Had a couple of "Wow" moments with stuff going on, seeing 4 jeeps barrel down the road into an enemy compound and then people dash out of them to take a forward position was great, and just as great was watching those jeeps and people then get ripped to shreds by enemy gunfire/rockets/grenades.
Graphically it's not going to win prizes, but it's very easy to get into the action and then it doesn't stand out.
If people like shooters though it's a definate purchase. To me it reminds me of the fun I used to have in Planetside. But like Planetside the commander role is a vitally important one if you want to win, and I've been unlucky so far and no-one's stepped up to the plate, but that said that doesn't detract from the fun, and you can see there is some planning and thought going on, which I could be missing out on as I can't get the headset I currently have to work reliably and won't be ordering the Logitech one till next month
You could try pre-ordering it from Play.com, getting into the beta, and then cancelling the pre-order