I have purchased 4 of these cases and have been pleasantly surprised by the solid construction and strength of them.
Currently they're used to store excess cabling however in the past I have used them for transporting, mains cables, XLR, microphones, small speakers, lights, and also used them to place amps on during performances, and as boxes to be stood on during performances (the latter wasn't intended).
They're generally great!
My only con would be the rather bulky corner guards (I can't remember the correct term). They make it slightly too large to line up nicely in the back of the Transit Custom.
Apart from that, I would highly recommend these.