I dunno about Taxiway's tours, since my dad knows a guy who works in the painting department, and gave us a private tour of everything, even the paint factory, where no one else usually goes
It was fun. The most interesting, IMO are the 320/300 lines. The 340 lines are big but not so interesting.
the "Cite de L'espace" SUCKS. Its a waste of time to go all the way over to the other side of Toulouse just to see it. It really doesnt have much to offer.