If I were in the market for low-production dusting and had only one choice, I'd get a Badger.
Air dusting removes more fine particulate but isn't as good at moving larger grit. Fine particulate is easier to remove during the cleaning process, so pre-cleaning removal isn't as critical as moving the heavy stuff. The biggest downside to the air system is the high cost of a compressor large enough to be effective, and trying to trap the dust cloud of that fine particulate.
I've found a pad sander modified to use a smooth plate works fairly well and removes more of the heavier grit than air dusting, and will be gentler on the carpet, but will take much more time than a strap-slapper to do it. You can get a pawn shop sander for $500, so might be the best product if you have more time than money.