Ok, I changed my order from Acer to Alienware for the following reasons:
1. Ability to tilt / swivel / height adjust the monitor
2. Audio out jack (for the audio output of a hdmi input i.e. my xbox 360)
3. USB hub (will come in very handy for plugging in the IR box of the 3D vision glasses)
4. 3 year warranty
5. Alienware monitor is available NOW.
In terms of quality of display, I've read that there's next to no difference between the 2 monitors - and that the quality is of a reasonable level. So for me the above points trumped the acer.
Sorry overclockers, I had to cancel the pre-order.