Absolutely I have but a) people I know with them have still had silly issues b) they came at it from the wrong end, Dell decided to adopt Ubuntu and did some minimal work with Canonical.

IMO Canonical needs to commit to a partnership with a vendor to produce a machine they can fully focus and support on, that way you get a product you know will just work and can be polished to a high degree.

The recent Dell XPS Dev laptops have been plagued with bugs/poor user experience. I'm not sure that's the go to anymore.