We have an oldish Toshiba currently, which is running Lightroom well but could do with an upgrade! We hide the laptop under the desk and use an external monitor with wireless keyboard and mouse (but we like the portability).
I keep leaning towards Macbooks, but to be honest I'm a Windows gal.
Budget: Can't justify more than $1000 (second hand is also ok)
Edit: I saw this one this morning, but can't find any reviews.