I'm not using this for bikepacking but everyday use. The cool thing about it is it has an inner waterproof liner that goes inside the outer bag. I put smaller items and tools in the outer bag first and then I can fit my inclement weather jacket and pants or gloves in the inner waterproof liner, and still have room for what I pick up at the store. Since you can compress the inner liner down as small as you need so you get kind of a three-layer loading system that works okay. There is also extra tie on space on top of the bag as well as an area to clip a tail light on.
The buckles and clips have a flip up lever so adjusting straps is really easy to do and quick.
As I look over the bags that I have had over the years that I still have and use are made by topeak. The quality of this bag seems on par or better than anything I've had from them and I expect this bag to last just as long.
I considered and handled other bags from other makers of this style of bag, but went with this bag because it was the right size, quality, and reputation that I have built a trust in.
Took it for a 350 mile test ride and it performed great. Plenty of space for a bivy, spare tubes, tools, device charging cables and a battery pack. Also had my armleg warmers and a base layer in it. Used the top netting for a spare tire and a bike lock. Feels very durable and the compression bag works great. The only downside is a bit of sway out of the saddle. Did not affect the bike handling at all.