Anybody using awning supports?

Hello all,
I am new to awnings, my older Class C did not have one, my newer Class C does. We like it much better with the awning. I have a 21 foot awning, I have installed a center support for when it is closed. I currently am also using the tensioning system that hooks to the roller bar and then straps, and spring connects to the base of the side rails. I was wondering if anyone is using any type of awning support/s to reduce sag in the fabric in the middle when the awning is opened. I have seen a couple on line at Carefree of Colorado, and also at CW. But, I am not sure if they work or if they are a waste of time and money.
Anybody using awning supports?

Nevermind, after looking at Carefree's site they recommend not using the type from, CW. The maunfacturers looks prtty good, so I think I'll go with that.
Thanks anyway