Best. Canister. Stove. Ever.
What more can I say? Its reediculous tiny. Flame control is astonishingly subtle. Remarkable quality and durability. Quite simply a masterpiece of backpacking equipment. Expect years of use and abuse out of it. I have used this thing above 12,000 feet in the Sierras and the only difficulties it had were due to the canister depressurizing rather than the stove itself. For the same reason, (as with most canister stoves that require an upright can), not sure I would recommend it in a winter situation.
DEFINITELY buy the windscreen. Its cheap and it adds enormously to the efficiency of the burner, especially above timberline. I also recommend narrow bottom pots, rather than the broad base type. The footprint of the burner and supports is quite small and wide 2-qt pots are a bit squirrelly.