hi, i,m wondering which g5 to buy, the 1.8 has nearly all the features that the dual 2 gig version has but does one get twice the computing power with the dual 2gig g5? that is is a dual 2gig the same as 4gig and therefore more then twice as fast as a 1.8gig machine? the dual version is only like 450 pounds more and if your getting twice as much power its surely worth saving some more for it? will it be twice as loud? and should we all wait for the updates? steve jobs has said that it will be under a year before we see a 3gig model, there will probably be some steps before that is reached and could mean that we see both price cuts and processer updates within 6months! what do guys think? please help me is you have some good advice on which model is the best to buy and why.. thanks andy.