I bought my first Svea 123 in 1979. I used it often for a few years before life got too busy to backpack. 32 years later, I was asked to go Camping with a few Army Special Forces friends. Aside from the fact that I had not changed the feul for over 30 years, that white gas fired right up! Once I remembered that one needs a proper headspace for fumes (e.g. do not over-fill), it was sputtering blue flame so hot that it melted the aluminum windscreen that came with it!. Fortunately, the base and wind scren are now Brass with new models. 4700 BTU is serious output without regard to altitude or temperature. I wouldn't trade it, sell it and in fact I bought a new one from Backcountry.