I want to start by addressing a common knock against mini pumps. Yes, it takes a lot of strokes to get the pressure up to where you normally would ride your tubes, but to me that's the beauty of this pump. It's incredibly small even for minipump standards, and it's got a controllable valve for threaded CO2 cartridge so you can start hand pumping first to make sure the tube is seated, and then use the CO2 cartridge to get to your desired pressure. I had to use this a few weeks ago after a particularly unfortunate descent, but it worked like a charm and I was absolutely glad I had this with me! Before this I used to carry a dedicated CO2 valve and a mini pump, but with this I've replaced two items with one, better functioning, smaller, and lighter item! Love it.
More than a year later this pump is working fine, The dual pressure mode makes it a snap. For those that find it tedious to hold a pump on a presta stem and inflate a tire look for a pump with a hose connecter - myself included these days.The rubber seal on the pump head sheds a slight bit on the valve threads but should last a couple more years before replacement is needed. A very good light pump for your seat bag.
Small version which takes a little more time to operate fits into a 1 liter seat bag suitable for rides (shrader valves) with the grand kids. The medium version is frame mounted for commuting and adult rides. Both do their job very well. Holding and operating a pump on a presta stem has its drawbacks. The connection hose has answered the need for these old hands. Works great every time and the pressure relief for presta valves is an added bonus. Well designed product for the price and if you can find a sale all the better.
I was expecting this pump to perform with a Schrader valve but to my surprise it did not. Maybe the sample I received was defective. I am glad I found out now rather than while out riding with my kids and when one or both of them have a puncture. I have a Blackburn air stick for my road bike that works great. It appears to be well made and I like the appearance, maybe I will order another one later, but for now I will go with different brand.