i have a 12" Orange WorkOut bag for my ibook. it was one of the best looking carrying case i have seen (we dont get that much selections here in vancouver, bc). The bag was very durable and i dont find the vinyl to be a problem with scratching at all. The bag is in between a sleeve and an actual "computer bag" so its very versatile (solo use or put the WO bag in another backpack). My 12" WO also fits the ibook snugly.
In fact, i just got another one for my SR MBP. However, this one is a bit funny. It seems like there's an about half an inch of space between my mbp and the top zipper (which i didnt find it in my old 12" case). I think the QC has gone down for Tucano over the year. I have noticed (in the store) that not every 15.4 cases has the "exact" physical dimensions.
anyhow, its a great bag. i highly recommend it (just bring your laptop and test it there before the purchase to make sure the fit). its a good looking and functional bag for sure.
cheers,
Howard