Wanted a slim fit case for my MBA and this fits the bill perfectly. Used for well over 18-months now and it has stood up to use over this time without any issue.
Nice, snug, fitting and the inside is soft enough to ensure no scratches for your MBA! Personally I use this to protect the MBA when placed within a laptop bag etc., to stop keys, pens, plugs etc., damaging the aluminium finish. Has some use on its own though if that is what you prefer.
Great price too - recommended.