I'm new to Macs & I'm wondering what each of these machines are capable of. What would I gain with the i5 & i7 over the i3 in practical terms (not necessarily the specs)? I know that's kind of a hard question to answer, but I'm just trying to get an idea. I do a little bit of everything with my computer, but nothing overly heavy-duty (although, I might someday). Actually, I'm not really asking what the best machine would be for me, but basically what each package will give me (if that makes sense). Also, which is the best buy, IYO? And is there something on the horizon better than the i7? I know I covered a lot, but any info I can get would be greatly appreciated from this Mac newbie.