I have used a Senior at my friends house, it is odd really because it is a cross between the powerplus and the ranger which I think both luck UGLY! I love the 652 in green, what a beauty, I can't wait to get my hands on one of those some day. The hose suction from what I have seen was pretty poor, although, I was quite impressed with the hose suction on the 70's Juniors, I thought it was very powerful for such a small motor.
I couldn't own a Senior Ranger for somewhat obvious reasons but I would love one of those gorgeous 60's, 652 Seniors, they are one of my all time favourites from Hoover.
Slightly off topic but I think the Hoover Turbomaster U5096 was the best cleaner Hoover ever produced!