I've played with soda can stoves, and still do a little bit. I've gotten one really good stove from all the effort, and it does boil water noticeably faster than a cat can stove. It is a basic, double walled design that needs a separate pot stand. I had made enough soda stoves that I cut everything right and it seals itself without glue.
Then I made a cat can stove because I was attracted to the simplicity of the stove plus it being its own pot stand. The first one I made worked perfectly, unlike the soda stoves. I've since made a few more, varying the number of holes and pattern, to play with heat output. The fastest cat can stove is slower than my one soda can stove, but I don't care about the two minutes "lost." Also, it's really simple to modify one while out because there's nothing complicated about the design.
As has been said before and in other threads, pot diameter makes a huge difference with an alky stove. I use an old MSR Blacklite 1.5L pot and the Imusa mug mentioned above. I wouldn't want to go any narrower than the 12 cm Imusa. I get flames going up the side with it, but enough heat hits the bottom that I get a reliable boil every time.
One thing to note is that my hole punch didn't last as long as the first stove. Making others broke the cheap punch I had.