You'll find a rotary a great piece of kit. I do use an Envirodri for agitation in most situations but today I was working in a hotel with a few rooms to do with a plan to post bonnet to speed up drying, it was easier to take a rotary in to agitate and then bonnet rather than take in two pieces of kit which eats into your time. For the money they offer great value but there is a technique to using them but once you get the hang of it it's quite straight forward. Get some bonnet pads and a brush as suggested and you can do some low moisture work too. I find the Envirodri best because of it's action the same as the Sebo, (which will do a good job if a bit under weight). A rotary spins making it a bit more difficult to agitate both sides of the fibre and you do need to take care to keep the brush/pad lubricated with moisture to avoid heat build up and damaging the pile. If it was a choice I would pick a rotary over a Sebo, but as you already have one adding a rotary will help you become more adaptable and you may find it better because of the extra weight.