You don't say where you are located, but unless you are in one of the few places where Dell doesn't offer on-site next business day support then XPS 13 is a great laptop. Their support is amazing: "We're not sure what is causing it, but we'll send someone to replace the whole motherboard tomorrow." "OH, your currently halfway across the world on a island? No problem, we'll be there tomorrow" I really don't understand…
Just make sure the model you're getting supports S3 sleep mode (AKA real sleep mode) before hand. A lot of the newer Dells don't. Its something the OEM needs to support in the BIOS, so you can't just fix it by installing a new distro.
I have one of those DELLs for work. Don't.