I have the Chocovision Delta and overall I'm very happy with it. I've been using it for almost two years and haven't had a problem.
I bought the Delta because of the additional features, but I'm not sure…"
It's possible your chocolates are spending too much time in the fridge, and the condensation is causing the sugar bloom. I leave my moulded chocolates in the fridge for no more than 15 minutes and I don't have a problem…"
"I also have a Chocovision Delta and I find that after several times working with the same chocolate, it loses it's sheen when tempered and develops thousands of tiny bubbles. I'm not sure why this happens, I don't have this problem…"