The Good: Lightweight
Easy to service
Secure thread-on valve chuck for presta and schrader
The Bad: Threads for chuck on pump base can get easily damaged or filled with debris when in use
Foot peg is small which sinks in soft soils and is unstable on rocky surfaces
T-handle is small and leads to my knuckles contacting the top of the air chamber at full compression in certain grip positions.
Flats suck. This pump doesn't change that fact but it does make the process of getting back on the trail much more enjoyable. Classic hand pumps require awkward bracing to keep the chuck attached to the valve. This pump does away with that by using a flexible hose and thread-on chuck so that you can inflate a tire without the risk of breaking/bending a valve or tearing a tube. Classic hand pumps also typically require so much shoulder and arm muscle to bring a large volume MTB tire to proper inflation that when the tire is finally aired up (after three rests to shake out the arms), you barely have the energy left to ride home. This isespecially the case with multiple flats. Not so with the Lezyne! This pump is basically a floor pump for the trail. The pumping action uses your whole body, not just your arms and shoulders to inflate the tire. This keeps more fuel in the tank for the ride and also makes for a quicker inflation time as you don't have to take breaks to let your arms recover.
When I first saw this pump in the showroom I thought it looked too big and heavy for trail use, and then I picked it up. It feels like a feather as it weighs only 150g! Once I felt the weight and was given a demonstration on how efficiently the pump worked, I was sold. While I haven't timed myself, I can say with confidence that this pump has cut down my inflation times substantially. It is especially noticeable when airing up a large volume 29er tire.
The Lezyne pump fits perfectly in the specified pump pocket in my Dakine pack and is barely noticeable. I have not used the water bottle mount so I cannot comment on it's functionality but I would reason to guess that it is not the best frame pump option as it's a bit bulky and the hose could come off if extra caution isn't taken to secure it.
There are a couple of things that I take issue with on the Lezyne. First, the threads at the base of the pump body that are used to secure the hose and chuck when not in use, get filled with small rocks and debris while pumping and have to be cleaned out before the pump can be stowed. Second, the foot peg is quite small which leads to instability on uneven or soft surfaces. Lastly, the T-handle is small which makes it a little uncomfortable to grip. I find myself switching hand positions frequently to avoid hitting my knuckles on the end of the air chamber.
In summary, if you dread having to air up a flat tire using a little dinky hand pump that wears you out and makes you look like a wanker, try the Lezyne. It's not perfect but it sure is a hell of an improvement over the alternatives.