I'm very pleased with everything about my home made alcohol stove with one exception. The top of the flames are approximately 7 inches high (from flame tip to stove top). This results in the flames "licking" up the sides of my cup rather than being concentrated on the under side. My boil times are generally 6:30 minutes for 9-10oz of water--this seems slow compared to other posts/reviews I have read, and I'm certain this is due to all the heat loss from the top of the flames doing no "heating work" what-so-ever.
The stove is a standard pop can stove, made from Red Bull cans (small). Burner holes were made with a plastic headed push-pen and they are spaced 2mm apart all around the circumference of the top of the stove.