What I did when I was searching for a laptop that would be my main BT system. I figured out the options before hand I ideally wanted i.e: 15.4 LCD, high native resolution, dedicated NV graphics card etc. With my list of requirements I did some research on laptops, to a short list. I then went to the wiki and read which had the least "issues" and/or minimal tweaking compatibility wise. I personally ended up with an older Dell Precision M60. Newer laptops aren't always the best choice as it can take a while for compatible Linux drivers etc to come out.
I don't know if that helps, but that's the method I used. I haven't have any issues with the Dell and Backtrack. I since bought an Alfa USB wireless as well to expand its wireless compatibilities. The Dell's internal has a broadcom chipset. Which is supported but can be a little temperamental at times. The Alfa is pretty much the #1 usb wireless of choice around here. There's no such thing as the perfect BT laptop, as everyone's requirements are different. If it meets yours and does what you need it to, that's all that counts.