The plastic connectors that aquadapter sell are great, they are extremely robust, I've trodden on mine numerous times, they are much more reliable than rectus 21's, and much lighter and I would say as strong and more reliable than the 26's.
They are the only connector that I have not had any trouble with.
Paul, just a thought regarding people trying the aquadapter. Richard who makes the aerial brush, sent out 1 demo brush for people to try, then they would pass it on to the next person.
Maybe you could have a demo aquadapter for people to tryout for a week, then they could post it onto the next person, that way people do not have to spend before they try? Just a thought.