I have a family member who wants to buy a Macbook Air in the very near future and has asked me to find the best deal. Looking around online, I found that I could buy a rev. B version for around $1000. However, is it worth it to buy the newest version with better specs for $500 more? I've read that the rev. A models (and somewhat the B ones) have had issues as far as heat and slowdowns, which makes me nervous. The computer is going to replace a small little netbook that just can't handle doing real work on the road. It will be used for displaying powerpoint presentations on the road, web browsing, and usage like that. That being said, should I buy this computer new or used? The family member is willing to pay the extra money if it's worth it. Thanks.