After 6 years of use, iMac G5 needs replacement. I am looking at i7 with bells. I am currently using around 350 GB of hard drive(out of 600 GB) in my G5 iMac. Can you please advise if going 2TB is better than 1 TB? It does not seem excessive to pay another £160 for 1TB internal hard drive space. Is it difficult in the new imacs to replace hard drives? I found the iMac G5 hard drive replacement quite easy. Thanks.