I have no idea how durable it is (stiches, belts, seams, zippers etc) but initial impressions: VERY thick padding and stiff back and lid, better than any gigbag I have ever tried.
It is like a glove, with two neck supports inside, bottom strap button reinforcement, semi-hard top part. Rubber bumpers all around.
Cons: very small external pockets. The gigbag is tight: Stratocasters/Telecasters fit, but you can feel, especially when closing the lid, it is like a perfectly fitted glove - if your guitar is bigger, wider, longer or thicker than standard Fender instruments, the gigbag may not be for you.
Conclusion: perfect for storing guitars at home, day to day commuting with your instrument, band rehearsals etc. It take less space than a case, it's lighter, if you bump against your 19th century furniture or car doors the bag will not damage it (those who use hard cases know the pain).
Of course you wouldn't check it in when flying - but I guess this is obvious. Neither would you want to stack other cases on top of it (if you store your guitars horizontally).
It is a bit pricey, but at least it feels like a quality product