I’m not sure what an rMBP is, but why selling the XPS? 8 years ago I had an XPS 17, it was about 4 years a constant shadow of mine, very reliable and one of the few laptops at that time that where capable of smoothly running a VM even on battery (well, only for 15 minutes or so, but you get it ;)).
Of course, linux is different to MacOS, but you will be able to use things you learned on mac, also you have a kind of freedom that neither windows nor mac will ever give you in how you wan’t your system to behave, to look, to feel, to speek… But maybe I am opinionated after more than 10 years of using primarily linux.
