The better battery usage and wi-fi are some of the basic things that don't work out of the box even on a preinstalled ubuntu on XPS are real let down. These are the same problems I faced when I had used Linux laptops before, and so now happily settled with 15" mac pro since past 5 years - no issues whatsoever.
I had forgotten my laptop while going through security at the Detroit airport. So when loudspeaker announcements happened, I went back to collect the laptop. The security guy asked "Why type of laptop is it?" intending to check if it's really mine, I replied: "One with lots of stickers". "There you go" he said handing me my laptop that was inside a protective cover.