I needed a bag to carry trumpet, flugelhorn and mutes, with rooms for typical accessories like oil, as well as a sheet music compartment. After much research and consultation I decided to go for the Gard 5-ECSK, and I'm glad I did.
The first thing to note is that this gig bag is astonishingly compact for how much fits in it. It must have been precisely thought out and measured; the manufacturing standards of Gard are prestigious, and this product lives up to them. My stuff fits snugly, but I wouldn't want it any other way.
I pack it with the trumpet on the outermost side, with some of the padded blocks on the edge of the case wedged around it. Then I place one divider next to it, keeping the trumpet secure, and the flugelhorn lies flat on the other side of the case, with the bell facing the opposite direction to the trumpet's bell. Then I stick the other divider horizontally above the body of the flugelhorn (attached to the inner side of the case) and place harmon, cup, straight and plunger mutes on there, as well as my trumpet stand. My flugelhorn stand has to go in the bell of the flugelhorn if I want to put it in the case, which means sacrificing one of the cone shaped pads and putting it elsewhere, but that's ok!
The bag is well made. Padded dividers could be a little thicker, but padding around the outside is adequate. Cordura and leather outer materials are good quality, and the raincoat is a nice touch. Stability is good so long as you pack it well, although it's never going to quite match that of a moulded case.
Backpack straps are of above average comfort for a trumpet case/bag, although that's not exactly a high bar. Won't be using the shoulder strap but it seems robust if somewhat uncomfortable by Gard standards.
Overall, very happy with the purchase - Thomann's web listing represents it accurately and the price is fair, factoring in that most gig bags and cases are pretty overpriced in general!