Markdini - I don't think anyone on TM has it yet - if so, they've not admitted to it
Here is the jibe thread regarding this item - you wouldn't have found it as it is rather derogatively named "Sankey's Sack"!
I'm sure the bag will be of reasonable quality, and probably is relatively well-designed. The question is whether you need to spend £15 on something a jacket or pair of trousers does very well anyway. Also, it does look nerdy. And the final test would be "has Sankey *ever* actually used this?" - all these points suggest something that has been released as a money spinner and not much more.
Having said that, Sankey goes with the American look of tailored shorts and trainers occasionally, so hey, maybe he thinks it's cool.