I had two of these and they both were DOA. Gave up in the end. Got a refund and went with the Samsung thumbnail sized ones instead.

they are 7dayshop own brand basically - so unless 2nd hand on ebay likely to be direct from them or via amazon etc

I had the same experience last month with 7dayshop. They refunded me quickly after I returned the item. Dodgy recent batch? I have 1 other I bought over a year ago, and it has been brilliant and pretty fast (varies, but always above 10mb/s) compared to 4mb/s USB 2 ones. Never had any compatibility problems with Grixx sticks, unlike MyMemory red USB3 pen drives.

Got one months back... Not working anymore. Survived a few formats and that was it.

In the market for several 128Gb drives.
How do these compare to this:
http://www.argos.co.uk/beta/static/Product/partNumber/3561869.htm

Speeds etc., reliability seems suspect on the Grixx model?

I've got both and found Sandisk to be slower in write speed. Both very good for price.

Not had mine long. Extremely fast compared to the kingston 64gb usb3 I own, which has a write speed so slow as to be unusable, this thing writes at around 110 MB/s.
I did buy it as a recorder for my sony bravia, but despite passing all the tests it kept corrupting so I went back to a hard drive.

Not aware of 7DS having any exclusive ownership interest in the company / brand Grixx Europe B.V. based in NL.