Your mtb tandem looks great (although the tires look a little on the fat side for me :^) ). I think you are correct that aerolite & spicer produce their frames in the same factory. I decided to go with Spicer, since I already had satisfactory dealings with Gene. Also, since Aerolite is a Canadian company, customs charges would have added to the cost. Further, I had some contact through TandemGeek with someone who had purchased an Aerolite tandem, and although they were generally happy, there were some things that they admitted were a bit sketchy in their dealings with Aerolite. It also came out that Aerolite was not using genuine S & S couplers, unless you specifically asked for them, and were removed from S & S Machine's list of framebuilders. If the need ever arises, I might get this frame retrofitted with S & S couplers, but not this year. My credit card has to recover!
Rich