I just purchased the Dolphin M400 and after one use I am very happy. I did not get the optional Remote because I didn't think I would use it. I now think it would be nice to have to get the cleaner over to the steps to take it out (I'm not as strong nor flexible as I used to be). The M500 Remote is only $10 more than the M400 Basic Remote so I am interested if anyone has tried the M500 Remote with the M400 and does it provide the additional functions the M500 has (scrub waterline, etc).
Dolphin M400/M500 Remote Control
- Thread starter poolhound
- Start date
What's wrong with dragging it by the cord? It's essentially weightless in the water.
As a retired engineer I believe "dragging by the power cord" is never the BEST solution. I think it would also be nice to just clean the waterline if it only costs $10 more. Since you answered a question with a question, I have to ask, are you a politician? 
Dragging by the power cord is Maytronics' suggested methodology for raising the cleaner to the surface; it's not as if I invented that.
I looked into this for my Tigershark pool cleaner. After doing some research - and calling the company that makes the Tigershark - I found out that you couldn't use a remote on a cleaner that didn't come w a remote. It wasn't built to be controlled by the remote and so it couldn't be used. You could only use the remote on the machines that originally came w the remote. Apparently they were built "remote specific".
The Dolphin M400 has an optional, at extra cost, basic remote available. The M500 has additional control features like scrub waterline only, that might be available with the M400 since the control/power box has the same part# for the M500 & M400. I'm hoping someone has tried to operate the M400 with a M500 Remote and knows if the M500 functions work.