The Rainbow still wins for attachment cleaning honestly.
I remember Tom telling me the only time dot absolutely no sand out of a carpet while demoing a Rainbow was a house where the woman had a Convertible of some sort, and she vacuumed several times a day, changing that C bag every use. Always felt Eureka had one up on Hoover with the F&G bag, and I'll confess to stuffing HEPA F&G bags in C bag Convertibles, but Hoover did eventually up them with the A bag.
The Guradsman is probably my favorite Hoover (second only to the 913/918) because of its use of the A bag rather than the C. Did any other metal base Hoovers use the A bag? Its also the best looking of them all in my eyes, and its far less common than the average Convertible.