Sir what unit do you run. and thanks for the support.When I was ordering mine , I went with a single wand model 23/47. I'm able to clean carpet and upholstery as a dual option. I did try dual wanding on carpet only, but failed. If I went 4 all the way, I believe that it would be a different story.
Did you talked to all small manufacturers and are ready to make an informed decision?
After processing all the informations ( a lot to take in) step back, sleep on it and then decide. Go with your gut, don't get entangled in to many whistles and bells, LED lighting and such. You need to set for practicality, functionality and willingness to maintain your machine.