MacBook Air vs Update current Lenovo G570?

Hi, I was wondering what people might suggest as far as computers go. I have a Lenovo G570 and my hard drive is about to go. I was looking at still state hard drive, due to the fact that they seem to last longer and are more efficient, but I hadn't realized how expensive they are. I'm debating just giving up on this laptop and going to a MacBook Air because it isn't a huge difference in cost. I was wondering if someone could help me figure out what the best option is between the following: getting a MacBook Air, putting in an old style hard drive to get it to just last me a year before I get a different computer, or to invest in a still hard drive. I really appreciate any opinions and suggestions.

With the MacBook Air price drop, increases in hard drive and ram amount as well as a better graphics card it would be a smart upgrade. Make sure you are okay with OS X and the programs you use go along with it. If all looks good from your end I'd say it's a worthy investment.