Hey guys I am having a bit of a dilema here as to which iMac to buy and am about to ask some seriously dumb questions as I am not exactly techy as it were. Firstly how much of a performance difference do you think there will be between the two 20" aluminimum macs. Secondly will i be able to play high definition video on these. Lastly is it worth buying now or waiting a few months for them to niggle the bugs out of these. My only reason for an urgent buy right now is that my bro is about to quit being a student in the next month or so so i want to try and make the most out of the discount.