Buy a T41p instead, and fly first class with the money you save, you should be able to fit it in up there.
The truth is it is all a balance. People who drive SUVs shouldn't complain about gas prices being high. You buy a certain equipment because you need it, and it will not meet everyone's needs. Obviously one shoe does not fit all. Those that travel all the time, will likely need a X40 type of machine. But those that need more computing power, but travels less, will prefer a T 14". And then there are those who need a 15" on the road, and do tons of graphs etc. I decied on the 14" for the size, and it has the similar computing power as a 15" R50p. If I wanted better screen to look at, I just hook it up to my 19" CRT. With a port replicator, it's very quick to do.