I've got a new XPS13 edition. There's a few downsides like I absolutely have to run the latest kernel - 4.5.0-rc7 - to not have iGPU issues and not all WMI keys being supported properly (running Fedora rawhide). But other than that, I get about a 7w/s power consumption without optimising anything. That makes for 9-10hrs of usage, even under Linux!

Oh, and repairing them seems to be dead cheap as well. My XPS13 took a little dive, replacing pretty much the whole ultrabook put me back 320 EUR.