I've owned a Royal for a couple of years and no other vac comes close to it, in terms of both "normal" use and back dusting. I've had a go with a rug badger, not as impressive in the flesh as the youtube vids I have to say :

On many rugs I reckon you can get as much or more out with a Royal, but it would take twice as long. There will be the odd exception though, such as very thick indian rugs that the royal just can't suck into itsslot enough to cause that resonant vibration that makes it work well... or very thin rugs that are impossible to keep flat without three people pinning it down for you.
If you're starting off with a low volume of rugs, the badger isn't a worthwhile investment just yet, and won't be until it's running for several hours a day with the higher volume. Get the Royal and you have a back-duster AND very efficient upright vac to do the face with. No-brainer really IMO

(there are compressed air dusters around too, I think only in the states as far as i've heard. Don't know about cost but probably need to be sitting down when you find out

)