all brands have their top and bottom of the line.
a $1300 brand X laptop is going to be better than a $400 brand Y laptop. it's not that brand X is better than brand Y, but rather a $1300 laptop is better than a $400 laptop.
you get what you pay for.
apple's products are made by foxconn and asustek, the manufacturers that make many other brand name laptops, usually in the same factories. apple products are built from no higher quality parts and with no better quality control than your typical [insert brand name] laptop.
for sony I highly disagree!!For apple I would say they are the top laptops in the market,though I hate apple and their policy.But as I said sony vaio=brrrrrrrr,for sony I have the worst opinion from dvd's to their highly overrated tv screens.
There are problems with Sony laptops but those are software problems and not hardware problems. The hardware is supposed to be good.
Other Sony products can vary of course. I bought a Sony TV based on internet reviews and it has worked well but in researching it I found that their previous model suffered high failure rate and Sony actually had to buy those back and replace them with the newer model. At the same time I was researching bluray players and discovered that the Sony model with the features that I wanted got bad reviews. However the original question was about laptop hardware, not TV's or bluray players.
Asus controls a lot of the actual product. They build motherboards, make graphics cards, and build the outer shell of the laptops. Plus they're smaller so they can't afford to botch a bunch of laptops. I'm a bit of a fanboy, but they seem to give you a nice amount of bang for your buck.