Lenovo w520 here. Running kubuntu 11.04. I have no issues with it now, but there was an issue until recently with Intel's speedstep and power management. They just released a new bios that seems to have fixed it. Here's a long thread on it: http://forums.lenovo.com/t5/W-Series-ThinkPad-Laptops/W520-S...
Other than that, it's a great dev laptop. Also keyboard and screen are great!