I've had my Dolphin Diag for 6 years now, and it has worked flawless for me.
I had to buy new clips last year that hold the bottom in the unit, and I bought another bag. My old bag is getting a little worn. It, by no means, is junk yet, but I liked the idea of having the 2nd bag.

One thing to keep in mind w/ these units, in colder water temps (I think it is <60degree F) the unit will not climb the wall. I know the first year I ran it, it wasn't climbing the walls. I got a little nervous it was broke, Once the temp warmed up, it was scrubbing the water line.

Only complaint I have is the cord twist problem. I change my handle directions, like instructed, but I have to untangle my cord almost everytime after I use it. The cable has some kinks in it now, which isn't helping the problem.

I would give you a thumbs up on the dolphin, I love it, and wouldn't be without it.

Blessings,