Runs 24/7. Super reliable. You just have to keep it cool - I underclock.
My current laptop is a 2007 MacBook. Not the solid-looking Pro aluminum kind. The cheap-looking plastic kind. It still runs everyday, all day long, and gets roughly 7h of battery life (with a spare battery) when I run XCode 4 (with real-time compilation going on) all day.
I can't seem to recollect PCs coming even close to that. Do they nowadays, or is the fact that you bought three devices as if this was normal clouding your judgement?
This is not to say whether or not their service sucks- I've just never needed to interact with their service department.
And then there are ODMs and OEMs: ODMs provide the designs, OEMs mostly just stuff boards.
It's common to find products of different brands that look almost identical, because the chassis are the same while the bezels are different.
Dell for example is basically just a sales force with a catalog, not much different in principle from CDW.