I got this pump when I upgraded a couple MTBs to tubeless. I love my old Topeka JoeBlow and got this because of the booster tank. It has a really long hose which makes topping off tires easy even when they are still on the back of the truck.
It is heavy, but thats good. Construction of the body and base is all metal so it should last a long time.
My only complaint is there isnt a handle retention device. My older Topeak has a flip up catch that keeps the handle down. This one doesnt, but I improved with some paracord and a buckle.
My Bontrager Flash Charger pump was stolen and I replaced it with a Joeblow Booster. This is a better pump. The handle is sturdier. The long hose allows you to fill a tire with the bike on a stand and the valve in an up position. When in pump mode, pressure is not equalized with the chamber like the flash charger which saves strokes. If you are riding in remote locations, this pump is your friend when it comes to seating a tubeless tire.
I use 700 tubeless tires and for a re-inflation test it didn't quite perform. I had to use the typical CO2 inflator or compressor.
For mountain wheels it may work better.
As a regular pump it performs well.