I got the thunderbolt adapter for my Macbook air because the place I was going to be at for a few months didn't have wifi. For the first three months of my stay I had absolutely zero trouble with it, but this past month it will occassionally disconnect but then a few minutes later will reconnect. It's been really iffy recently, and I've been a little bit concerned about plugging it into my computer. Hopefully I won't need it for too much longer, I'm not sure if it is meant to last more than a few months!
It is a very fast adapter, bought it for my rMBP to use at uni. the issue is that it falls out VERY easily, which is somewhat of an issue for me. when working at a desk its fine, but at other times it gets knocked even just a little and it disconnects and takes a while to reconnect. This is annoying!