I just bought a Dell XPS 17" for essentially this purpose. My friends call it a "shleptop"
It's huge. But damn, it's fast. Did I mention it's fast? And a huge screen? Oh, and it was only $1300. Only downside is it maxes out at 8GB of RAM. The only way to get a 16GB model is to get the 3D display, which I didn't want and took the price (with mandatory extras) up to something like $1800. No, I don't have an IPS display, but honestly, I just finished calibrating it and it's good enough for on the road work. Heck, I don't even have an IPS display yet on my desktop.
If you are willing to spend more nothing beats Lenovos for rock solid reliability. But the price/performance tradeoff for me meant I went with the Dell.