This argument drives me crazy! The CPU speed is probably one of the least important things to me, basically any laptop sold today is fast enough. What I care about is weight, build quality and battery life.

The macbook air weighs ~1kg, has a 12 hour battery life, and has a nice aluminium body. Last time I looked, not only is it impossible to get a PC laptop like that for a comparable price, it is impossible to buy such a laptop from any PC manufacturer for any price.