Thanks for all the responses! Yeah the super Mini is a renaming of the super midget. Do you have any pictures of them stacked? I kind of wanted to see how they align aesthetically. The pics you posted are great for seeing the size difference!
It sounds like most people don't mind taking the BB3 most places. I sometimes play some smaller brewery gigs where we cram into a corner and a smaller cab works well, but it doesn't seem like there would be a very appreciable difference between a BB3 and SM as far as that goes. I'm looking forward to trying out just the one BB3 at some gigs to see how it fits in the car and moving around.
My biggest problem with moving the BB2 was the "bulk" of the external dimensions but not really the weight. It's not the most convenient shape to carry but that gets largely offset by how light it is. I'm assuming a BB3 is fairly similar. Also keep in mind that I have some strength and mobility issues.