I'm not saying it isn't, but first time I booted it up it took me a good 20 mins to figure out how basic things worked and I'm used to using weird Linux DEs.
I don't think it would leave a great first impression on your average ADHD alienware target customer.
You do need to learn a few keyboard shortcuts before you can work effectively with Gnome 3. I think these ones get you 80% of the way there, though (and they work the same as they do on Windows):
1. WinKey and type a name to open programs
2. WinKey + arrows to snap windows
3. Alt+Tab to switch between open windows
It's really a shame, because it really takes almost no time to learn. And basically the point is that the desktop disappears and the only thing left is your work.
Edit: Or entertainment ;). Point is application is whats important.
Keep in mind that these entertainment computers may be plugged in to living room TVs, which will often not be used with a keyboard and mouse, but perhaps with a game pad or remote.
I don't think it would leave a great first impression on your average ADHD alienware target customer.