The 7 series has one of the best motors you can put in a vacuum today, Double fans, double ball bearings, huge commutator - that motor is bullet proof. The steel brush roller with replaceable brushes is an excellent agitator for a vacuum, grooms and cleans very well.
If you buy the machine, let me know. I can get you HEPA bags, new brush strips, a new lower cord hook, and the attachments, for the wholesale cost of the parts. It's DEFINITELY worth $20. Once you fix it up it will become one of your favorite vacuums. Yes, it's slightly heavy (about like a Concept 1) but is the perfection of the by-pass upright design.