Cons: This thing SUCKS. I lugged it around on my frame for a hundred miles or so and then one day, when I actually needed it, I couldn't get enough air in the tire to even limp out to the trail head. Way over priced for a product that doesn't work.

Recommendation: I would not recommend this pump to anybody.

Pros: Lightweight, high volume, pressure gauge

Cons: Locking the valve stem, pressure valve

Recommendation: I've had good luck with this pump. It pumps super fast and although it has a pressure gauge, it's not very accurate. It is better than not having one though. It at least gets you in the ball park. It is kind of a pain in the ass locking the valve stem on.

Pros: Decent size for a pump, easily fits in my pack.
The dual head seems to work pretty well for either valve type.

Cons: I have never successfully pumped a tire up to decent pressure with it.
High Volume / High pressure switch doesn't seem to make much difference.

Recommendation: I got so mad at this stupid pump that I finally got a CO2 inflator. Now I wonder why I ever even bothered with a pump.

The Genuine Innovations Air Chuck, with a cartridge, is 1/2 the price of this, and inflates a 2.3" MTB tire in seconds.

Pros: Comes with frame mount.
Light weight.
Gauge.
Dual pressure system.

Cons: Rotating head only works in one direction

Recommendation: This is a great emergency pump. I got mine for $15 so is a steal for the price.

Recommendation: For emegencies the pump works pretty good. It is compact in size which is both good and bad. Good-as it is light weight and easily stowed in a camelbak or shirt pouch. Bad-The compact size makes it a bit cumbersom for someone with larger hands.

Recommendation: Works pretty well. I like the adjustable inflation pressure. Downside is that the rotating head is somewhat confusing as it rotates both directions but only works properly in one direction.