Another online magazine did a side by side comparison of these three beasts just last month. Obviously the Sager equipped with a quad core and SLI came out ahead in pretty much every benchmark and for less money but the Sager can be equipped with lower specs such as a dual core or single CPU such as I have done with mine. It will still be a powerful machine but for much less money.
Appearance is subjective of course and it depends on what you are looking for.
You can read my review of the Sager 9262 here:http://www.notebookforums.com/thread220194.html
And read Steve's here:http://www.notebookforums.com/thread215207.html
Both are the Sager 9262 but with very different setup and specs.
The Sager brand has been around a long time but like Alienware and Dell they are just a company that resells components made by others. Sager offers much greater flexibility in configuration and depending on where you buy it you can configure it exactly the way you want and even order it without a pre installed operating system which is a huge plus for those who already have a transferable Windows license and like to setup their own installs or don't wish to use Windows at all. Dell and Alienware like all mainstream brands like to toss in a lot of adware and trialware on your new machine to make a few extra bucks profit on the sale. you would think this would allow them to sell the machines cheaper but it doesn't seem to work that way.
I can't say much about customer service with Sager because I've never personally had a problem with my Sagers and have never needed to contact them (/me knocks on wood).