Dell Latitude's work well. I'm currently on an E6320 with Xubuntu 14.04. I've removed the DVD drive and replaced it with a 2nd SSD so I have dual SSD's in a 13"

Dell Latitude's work well. I'm currently on an E6320 with Xubuntu 14.04. I've removed the DVD drive and replaced it with a 2nd SSD so I have dual SSD's in a 13" laptop. Everything works perfectly including the docking bay which allows me to plug in a 27" monitor at 2560x1440 via Display Port. Multi monitor switching works better than Windows 8.1 for me since it's hot swap and the windows retain sensible sizes for when the larger display is plugged back in (they all instantly resize in Windows). The new E7440 is very nice and can be had for great prices on eBay. I tried one of these with the Full HD IPS screen. Unfortunately I couldn't get HiDPI to work to my satisfaction (even with latest Gnome and KDE). Having said that, I couldn't get Windows 8.1 to work to my satisfaction either.