You're right about reduced quality. If that is an issue look at the Toughbooks but you do pay for that.
Some business models are not built any better and use the same parts so no gain there.
Let's grab what we can about steering clear of common complaints. If this is a laptop that we plan on traveling or moving it around a lot, I'd avoid 17+ inch screens and the i7 CPU. The size is one that I hear a lot of complaints about for travel. And all the i7 based models (so far) have very warm surfaces and low battery times.
Try the i3 and i5 machines and try to find units that are not too "bendy." That's not a lot to go one but flimsy bendy units tend to be those units I see die sooner.
--> Here's the big item. Many expect ZERO maintenance machines. I expect to do my yearly blast with canned air to keep my machines cool and happy.
I'm looking to replace my dell inspiron 1420 which is about 2.5 years old now. Based on what I've read and personal experience, there doesn't seem to be much difference in quality or reliability between brands, so I'm not worried about Dell vs HP, etc. I'm just wondering if there are certain things I should be watching for though - notoriously bad components I should avoid, or minimum stats on the processor for example. I am definitely going to shell out for the longest warranty possible.
Also, would it be worth looking at "business" models?
FWIW I'm looking for a 14ish inch with windows 7 and will be doing mostly internet and some graphics stuff and that's about all my criteria.