I'm typing this on an X230, with 16GiB RAM. I busted the screen recently and considered an X250... it's such a shame that "ultrabook" means "one DIMM slot" these days, i.e. they max out at 8GiB RAM - same as I was using in '2009 on my old X61s!
Luckily replacement screen parts are quite affordable these days. And before anyone complains, I do use all this memory, currently dom0 has 4GB free.
Good news! There are 16GB SODIMMs from "I'M Intelligent Memory". You'll have to look around to figure out what model exactly, but people have put them in new X series and they work.
Luckily replacement screen parts are quite affordable these days. And before anyone complains, I do use all this memory, currently dom0 has 4GB free.