I am a debian user and use the same hardware. HP 6515b. I also got a sluggish performance after update. Thus before I decided to wipe out my os I tried upgrade my dist to be testing or wheezy. After 30 hr. waiting for it to upgrade itself. My system become healthy as usual except BCM4311 module that I must reinstall as following link http://wiki.debian.org/wl Hope this help. Regards Sarit