As a general rule I’m not in favour of CO2 to inflate bicycle tires. A pump is cheaper in the long run and does run out if you have 2 or 3 flats in a row. Plus I don’t feel great about sending CO2 cartridges to the recycling depot.
Having said that I do own a Planet Bike Red Zeppelin CO2 inflator. It lives in my Bike Friday Tikit’s seatbag because there is no handy way to attach a pump to this folding bike, but I still want some inflation capacity onboard. In 3.5yrs of service I have finally got a chance to use this inflator when I had a flat the other day.
The Red Zeppelin worked as advertised. One 16g cartridge inflated my Tikit’s 16″ x 40mm tire twice. The conrol knob allowed me to use as much CO2 as I needed and then shut it off so I could use the rest later. I filled both Schrader and Presta valve tubes.
My advice is to use a pump whenever possible, but if you are going to get a CO2 inflator – you might as well get one that works!