I have the original Jetboil. It's neither as compact nor as light as an alcohol stove, but it's a good stove.

The Jetboil has a lot of in-built wind resistance whereas an alcohol stove is very vulnerable to wind unless you've got a good windscreen. On convenience, speed, and wind resistance, a Jetboil wins hands down.

On price, reliability, compactness, weight, and availability of fuel, the alcohol stove is the clear winner.