Yes! That was me. I have not thought about getting a desktop. I study astrophysics and I travel a lot so I require a well-built moderately powerful machine with good battery life that I can take with me anywhere. For most my work I SSH into the maverick supercomputer at TACC to look at data from the Hobby Eberly Telescope. The XPS 13 has been sufficient for that purpose. Surprisingly, the XPS 13 holds its own multiboxing 6 characters on FFXI for hours at a time. Does it get loud / hot? Yes. But the notebook cooler helps. And a small part of me really loves to see how far I can push this first generation ultrabook. 
At this point I am strongly leaning toward the Dell XPS 15 based on my prior experience with the reliability of the XPS 13. I found this video demonstrating the graphics card used in the XPS 15: https://www.youtube.com/watch?v=AiyYdMH7cN0
This leads me to believe that the XPS 15 will be more than adequate for casually playing older titles like EVE and FFXI. I will probably go for the FHD version for readability of fonts, and for lower power consumption / less heat / longer battery. I will continue to use an external notebook cooler when working under heavier loads to support longevity of the computer. In any case I will probably wait a couple weeks to see if Dell has any plans to update the XPS 15 with the new 8th gen core i7 processors.
Again, thank you all for your perspectives. 