I'm glad that someone has raised this topic, as I'm looking into buying a laptop as well. A few people have warned me off saying that they are unpredictable and unreliable in live scenarios, but I have also heard a lot of positive feedback too. Unfortunately, I'm on a fairly tight budget and am looking to spend around £750 - £1000.
I've had a look at the 1.83ghz Intel Core Duo MacBook, which comes with 512mb memory and 60gb hard drive for around £750.
Only thing is that I've never really used a Mac that much and it would mean buying new software as well. I looked for a Sony equivalent and found a Vaio with a T2300 Core Duo (1.66 ghz), 1gb memory and 100gb hard drive for about £820.
What I'm really asking is, do you think that either of these machines will happily run applications like Reason 3 and Ableton Live, or am I just dreaming?