If we are talking about the Macbook Air, Apple's build quality can't be beat at that pricepoint. If we are talking about full sized laptops, a Macbook is almost absurdly expensive for what it offers.

I've had Asus, Samsung, and Alienware laptops that were built just as well as a Macbook, yet cost a fraction of the price. In addition, the specs exceeded a top of the line Macbook Pro by a longshot. The Asus and the Alienware were really ugly, but the build quality was exceptional.

If I were in the market for an ultrabook, I'd easily pick the Macbook Air. If I wanted a well built desktop replacment, I'd consider the Macbook Pro, but I would also take a look at Asus, Samsung, Lenovo, and even Alienware* before I make my final decision.

On a final note, the specific model if far more important than the brand. Every PC manufacturer has good models and bad models. If you find a specific computer that you like, you should check out as many reviews as you can find on the internet before you buy it.

*I'd stay away from Alienware if you can't handle the hideous design.