Well remembered, vacbear! I never did see one myself, only pictures, but yes, they were sold as the Goblin Roto.
Regarding the Hoover Sensortronic, I could be wrong, but I don't think they sold all that well, hence the infrequent sightings. If one thinks back to the early 1990's, there was with such an enormous choice of cylinder cleaner, both within the Hoover brand and also outside of it. On top of that, Vax was still selling in great numbers, and competing on price with the Sensortronic were the likes of AEG, Bosch, and Meile, all of which were becoming ever-more available, what with the like of Argos now stocking them amongst others.