Since my PC sudden death, I thought to replace with a new iMac 20". My needs are serious photo editing on photoshop CS4 and some video editing from time to time. I was dissapointed to find out from reading over the net and here also that some people relate to the 20" screen as bad. Is it really that bad? I'm on a budget here and the 24" is out of the question. For the same price I can have a good screen and a powerfull PC what would you reccomend?