Short summary: I have a first-day Rev. A 1.8/SSD. I was running out of space on the stock 64GB SSD, so I upgraded to a PhotoFast 128GB SSD. I was happy with the space, but not with the performance. I love the MBA, and want to get another couple of happy years from it, so I gave myself an early holiday gift and upgraded to the RunCore 128GB SSD. Here are performance summaries for all three drives (using XBench): In graphical form: Just for grins, I also tested all three using an external USB enclosure: In graphical form: Clearly the limiting factor on external performance is the USB interface (I don't know where -- driver, USB enclosure, etc.). In short, the RunCore really is a screamer. Even compared to other SSDs, the speed increase is definitely noticeable. I can also say with complete certainty that I cannot imagine going back to using a non-SSD system . I purchased the PhotoFast from DV Nation, and the RunCore from MyDigitalDiscount. I had good experiences with both companies. The RunCore includes an external USB enclosure as part of the package, which is nice. The PhotoFast does not, though an appropriate one can be found (I found one on Newegg from StarTech). The RunCore enclosure is a bit less sturdy then the StarTech, but it's also slightly smaller and lighter.