Brushrolls...
Regarding the Elite style brushroll, there were 2 types. One had brushes all the way around, the other is what Jack describes with the 1 brush strip, 1 beater bar. The latter was truly a pathetic attempt at a brushroll....the double brush version cleans about a zillion times better!
Regarding the glued-down carpeting....I'm sorry but NO vacuum seems to do a very good job on the glued-down carpeting. I've used many, many different machines (including a Windsor [Sebo at heart]) on the glued down commercial garbage, and nothing was very effective at getting dirt OUT of the carpet. You can get it OFF the carpet, but not OUT. Big difference.
And no.......the Kirby doesn't do a job worth a flip on the glued down carpeting either. I've used multiple models at our production facility, and hands-down.....the best cleaner we've got out there is a cheap Eureka 1934A fitted with a 4-row Vibra-Groomer II. NOTHING can touch that vacuum on the commercial carpet.....not even the Kirbeast. Even the 7 amp Sanitaire is just too powerful, it doesn't let the brushes do their work enough.
That said, we have to wet-extract the floor 2-3 times a year to get all the dirt out that just falls below the nap. If air can't get behind the carpet backing, it won't clean all the way through. Simple physics.....