i have a 5 year old iMac and Im ready to upgrade to one of the new 27" iMacs. One of the main problems I have with my current "old" iMac is that years ago video editing was great but with time, the new video editing softwares dont run as well on it anymore, its slow and sluggish, and editing HD video can sometimes be a little frustrating as the machine has a hard time keeping up. rendering can take an eternity! anyhow... my current iMac has 128MB of video ram, and with the new iMacs I have a choice between the less expensive model with 512MB of video Ram or the more expensive one which has 1GB of video ram. I dont know what to go with. I cant afford the more expensive model right now. i'll have to wait atleast another month to save up. but I can probably buy the "cheaper" one ($1699) with 512MB of ram right now or very soon! i just want to make sure i buy the right one. will i see a drastic difference in speed between the two? particularly with video editing??? i edit alot of HD video and I'd like my new machine to handle editing well... QUICKLY... efficiently. sometimes the "rendering" on my old machine will take so long i leave the room and come back 10 minutes later and its still going... once i tried to add stabilization to HD video in Final Cut Pro and it said it would take over 30 min just to analyze the video. that cant be typical?! i rather save the money if the cheaper one is going to be more than enough video ram for editing... but if i really "need" that 1GB of video ram... then should i keep waiting? video ram is one thing i dont know much about.