I haven't tried it at altitude yet. I have been quite satisfied with it at ~sea level. I tried some of these with normal resevoirs and found that I didn't get through a pack of cigars without exhausting the fuel. These really use up a lot of fuel. Mine has a small tank look to it that has held up well. The flip-top broke off somewhere but that hasn't been a problem to me yet. I will be hiking the whites a lot this summer and should be on some 4000+ elevations then. I'll let you know my experience.

I'd expect that the butane with the little screen will work at any elevations that the bic's work at and the added feature of the hot screen maintaining the flame will provide a welcome bit of wind-resistance.

I find these at convenience stores at the novelty sections by the register for less than $4.00 ( I'm a cheap guy)