Currently I am building a new system with 2 Seagate 7200.10 320gb. Fry's has the rebadged Maxtor's for $60. I am timkering with the idea of buying 2 more. I am not completely sure, but beleive 0+1 will improve performance and will provide backup. So I will have 640gb avaible with the other 2 drives as backup. Is that a good idea? Or should I just save my $120.