What about the Electrolux Z500 series? They're gentle, but then so are the Oreck XL uprights if you can stand them. I wouldn't say my old Senior or Junior is particularly good for soft delicate rugs -they tend to either have belts that snap on the rug if it slips all over the floor, and if its a thicker rug that more or less doesn't have that issue, then the beater bars have a tendency to flatten the pile down. At least with the Oreck's brushes, they're a lot softer.
Ive said it before and say it again, Oreck's brushes/general brush roll is a fantastic groomer - but the noise puts me off Oreck to say the least.