It appears to be focused toward heating and chilling engineers...
With the Rothenberger Roxy 400L I'm using a quite similar kit in just such a trade (refrigeration & a/c):
http://www.ebay.at/itm/ROXY-400L-HARTLOET-UND-KLEINSCHWEISSGERAET-Rothenberger-/110365237315Note the larger, 3ltr oxygen tank on this, providing durability...
Also have the adaptor for the smaller, disposable oxy "cartridges" as seen on the Castolin, but only as emergency backup as they empty
really quick! I can do 2, maybe 4 joints with that small oxy tank...
Another issue are ambient temperatures on the butane cans; for safety the gas is dissolved in acetone (the liquid you notice when shaking the container), if its colder the avail gas flow, thus flame size and therefore the performance drops drastically...
When nearly empty the acetone (or something else inside) seem to foam-up, so the burner starts to spit droplets, yet even stalls due to the clogging... so always have a fresh, spare can around.
Quality of tank connectors & valves is also not the best; I've the routine to always remove the valve from the butane bottle, to avoid the stench (and possible fire risk) in the panel van/lorry...
Definitely OK for
brazing copper lines, even up to 28mm fittings, I love it over its compactness and low weight, but not sure about using it as substitute for a real acetylene
welding kit on thing like a steel motorcycle frame... might take just too long to reach the melting point of the steel and the wire...