as titled, Could you guys please state out the advantages and disadvantages of an 27" iMac possibly with QuadCore i7, 8Gb ram, others are default. main uses: internet browse, sketchup, photoshop Still doing some researches about iMacs, just in case I regret in the future. ps, are iWorks, Aperture 3, and AppleCare necessary? I mean, apart from AppleCare, are they downloadable? Thanks guys!