Well thats how the vendors operate, most of them, different type of service for business users and consumers.
I have also found this to be the case.
Old Inspiron laptop = utter crap.
Old Latitude laptop = pretty good service
Mother's current Latitude laptop, must be 4 years old, I swear they have replaced the entire machine twice by now. But they keep on fixing it for free! Still a crap notebook tho.
Old Thinkpad i1300 (truly the crappiest Thinkpad around) = still good, they replaced the motherboard for me even thought it was a month out of warranty
T60 = good, new battery, new screen housing, fast too, etc.
Mitlov's Ideapad = obviously bad