We have a 10ft Avon Rover with wood floor and a Cadet FR with the air floor. The Avon is old but very serviceable. It would be considered the best buy in the long run, but both have their advantages.
Seems to me your choice is more between the floor construction than the boat brand. I would compair depending on the way you plan to use the boat. Although the Avon is a class act, the Zodiac is still a viable choice.
Do you want a lighter boat with an air floor or a hard floor? The hard floor boats can use higher horsepower motors. The Hypolon is a longer lasting material but more expensive.