Part of the issue is that the Sputnik team has to take the XPS 13 hardware as is (as it was designed for Windows) and try to support it. They are releasing the drivers upstream (at least they were when I last checked) so that's awesome! But it meant I had crazy stability issues until the 3.19 kernel release.
The newer models of the XPS 13 DE seem to have better hardware for linux (Intel vs. Broadcom wireless for example) so it may be better, but I would still encourage anyone looking at the Sputnik projects to consider the Precision M3800 instead (15" workstation version of the XPS 13). There are also some other Dell workstations available now that might have better hardware for Linux.
Edit: Also I have owned a couple of System76 laptops and have had 0 issues with them out of the box. But their drivers are proprietary (AFAIK) and their chassis are Clevo...so definitely not in the same ballpark as the XPS when it comes to build quality.
You also might try virtualization. With paravirtualized drivers, and VT-x support in the CPU, you run at near native speeds, and it is all very stable.