The trick is that all home-grade machines, I don't care who makes them, are shit. (Apple is weird, and is the exception to everything in this post, as they don't really have a "consumer" and a "business" line, although they're more consumer-oriented. But their machines tend to be built with something resembling quality, unlike most consumer machines. Which is why they cost as much as everyone else's business machines.)
Business grade machines are where you'll get something durable and meant to be repaired easily. Then again, you can get the odd lemon... (case in point, the OptiPlex GX280, or GPU failures on the Latitude D630 (then again, literally every laptop manufacturer got hit by that one) - I can do D630 boards in 21 minutes.)
And, business support tends to be better than home user support (even if you're just buying a business-grade machine), again for all manufacturers, at least in the US.
I'll note that #iwork4dell (yes, the hashtag is obligatory, I know), providing on-site enterprise support. Basically, the client that I support pays a monthly fee, and gets computers, dedicated people to install and maintain them (literally, I work 8 hours a day at my client's local facility, and support no other clients), a US-based helpdesk dedicated to them, and even on-site parts, and a 10 business hour (with some exceptions) service level agreement.