Final comment here - I believe the Bulldog variant listed above should clarify that it uses lightly-aged rum, and isn't distinguished from the Colorado Bulldog simply by the glassware.
I decided to try the "Mother" listed above as a variant - it wasn't on the website, so I did a few minutes Internet research, mixed one up and then posted it to Difford's.
I don't care for vodka much, and I didn't much like this either. The foamy head delivers a pretty prominent taste of raw alcohol that I didn't like. If you like vodka - you could very well like this. I also found that I liked this better when I added 2 oz (60 ml) or Coke, vs. the 1 oz (30 ml).