We have one of the Alienware X51 bundles off of Amazon. All of the programs we have tried seem to be working fine. However, about 75% of the time when the user removes the headset the PC seems to freeze - the mouse cursor stops moving on the screen, hitting keys on the keyboard seems to have no effect. The only way to move forward seems to be to hold down the power button and cause the PC to power cycle.
This would just be a minor annoyance, but quite often it seems like game progress doesn't get saved when the PC freezes up like this and so the kids have had their game progress reset to the beginning a couple of times.