Strengths: This thing is tiny, light, and better than others I've used. I just bought a second to replace a Rav X, which was no good. I find the valve on this guy works well so that there is no leakage.
Weaknesses: There's this mumbo jumbo about only using branded cartridges. I'm inclined to ignore.
Those these could probably be a little cheaper, I would definitely not choose an inferior product to save a couple bucks- much better to feel confident about inflating to desired pressure if you have to use it!