You have 2 different needs. The carpets need a powered brushroll with height adjustment for the best clean and the delicate rug needs a lower suction brush without a brushroll. Here's a few options:

1. Hoover T-Series UH30301 $199. This is a capable basic upright vacuum with carpet height adjustment and brushroll shutoff. It will be great for the majority of your carpets. You could turn off the brushroll and raise the height for the rug, not sure how it will perform on your specific rug. Or you could get a Wessel Werk D272 $21 and attach it to the wand, with the brushes up it will slide on the rug but won't beat up the fibers. The Hoover doesn't suction control so the D272 might get stuck to the rug.
2. Sebo Felix $699 is the BIFL option. This is a durable and repairable upright vacuum with swivel steering, carpet height adjustment, brushroll shutoff, AND suction control that works on the powerheads as well. I would turn off the brushroll and try to match height and suction to get a good clean on the rug but not too aggressive. The major advantage of the Sebo Felix is it will last 15-20 years and you can do most of the maintenance yourself because Sebo sells most of the parts directly to you. Cons are it has a short hose and is slightly top heavy. If you can test one in-store, that way you can feel the price difference. The cheaper Sebo Dart doesn't have suction control.

Thoughts?