Personally, I love them. They cut my work in half on whatever I'm making as those are rings that I don't have to close myself. Four stretchy HP 3-1 bracelets are part of my daily "mailledrobe"
From a business standpoint, I do feel they "cheapen" the jewelry a bit. The only time any of my maille has been mistaken for or compared to those damn loom bands are when I use rubber rings as a component. I've found that maille with rubber rings are also much more prone to be looked at as "kids jewelry" and people expect it to be priced accordingly.
I started using them recently (got them as present) and still deciding what I want to use them in. Items are not yet for sale. This is something I am currently working on, and hope to be finished soon. I think if you make smart decision about color and weave it won't cheapen your work, just add to variety.