[ATsch]

I use a x230 with the biggest battery. It's decently thick/heavy compared to the modern ultra-slim laptops, but it's compact, fast enough and it set me back barely over 300€ total and the battery lasts 9+ hours.

It sounds like budget is not your problem, but I thought I'd just mention this for any students etc. passing by.

[TimmyMustGo]

I use a x220 because it has a better keyboard. I'm limited to USB2 but honestly I never use them except for my mouse and iOS devices, which are limited to USB2 speeds anyway. But I'm able to hook it up to dual external 1080p monitors. Cost me less than US$100.

[ATsch]

note that you can also use the x220 keyboard in the x230.

x220 keyboards are a bit hard to source for a good price, though.

[wilsonnb]

If you get the x220 with an i7 it comes with a single USB 3, in case anyone is looking to purchase one.