ArsTechnica provides an extensive walkthrough and installation of the OWC MacBook Air SSD replacement kits. The OWC Mercury Aura Pro Express is the only presently available SSD replacement for the MacBook Air's new compact SSD drive.
Installation requires some disassembly of your MacBook Air as well as the lengthy backup/restore process to migrate your data. The new drive offers some performance benefit over the original Toshiba SSDs, and is about on-par with the recently shipping Samsung SSD drives.
The main benefit for the replacements are increased storage capacity, but it comes at a price with 180GB/240GB/360GB drives costing $499.99/$579.99/$1179.99 respectively.
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Top Rated Comments
I have to disagree with some of you who seem to feel the product won't even succeed at these price-points.
I've been in this industry long enough to know that there's definitely a segment of the market out there who can afford to buy something like this -- and it's a segment somewhat likely to already own a Macbook Air.
You can compare the cost of the SSD to the cost of the whole machine and argue it's "ridiculously overpriced" from that standpoint -- but that doesn't tell the whole story. CAD designers and 3D animation people have been buying video cards that cost more than the entire rest of the computer they sit in for years and years.
For someone who really likes the lightweight, portable nature of the Air and feels that the only thing it lacks is sufficient fast storage space? They might very well say, "Sure, I'll pay another $1,000+ to have 3x the storage capacity it came with originally, and faster storage at that!"