there is always a computer faster than the one you just bought. the only thing you have to do is wait a few weeks. and if apple does not watch out it wont take long til they are outperformed.
but the question is - can you afford to wait? who pays you the time you waited for the faster computer, which in turn is outdated in performance and/or price soon too ??
if you dont mind money, then get the machine that suits your needs for as long as you need to save the money again for upgrades or a new machine. if you really badly want a mac, then better start saving big bucks now