I have an 11" i7 MBA arriving sometime in the next few days. It's a long story, but I have the opportunity to upgrade it to a faster SSD at no cost at all to me. I know very little about SSDs; is there anything faster on the market that would make an upgrade worthwhile? What kind of speed increase would I be looking at? What specs do I need to keep in mind when looking for something suitable? Drive capacity isn't too important to me in this instance. 128GB is more than enough as I keep all my files on a Mac Pro. It's a performance increase that would make the upgrade worthwhile. Thanks.