FPG,
Everybody and every pool is different of course, but I like the idea of not using my robot unless the pool needs it. It tickles me how many people spend weeks trying to decide what waterline tile goes with the color of the plaster and what plaster goes with what color decking.. Then they dump in an ugly cleaner and let it stay in the pool 24/7.
I personally like the idea that I don't see my robot in my pool, unless the pool needs to be cleaned. Most of the year, I only put the robot in about every thee days.
That said, you can leave the robot in 24/7, if that is what you want to do, but you will have to take it out to clean the filters. This could be every few days, if you have a lot of debris, or up to two weeks if you don't get much "nature" falling in your pool. The timer on most robots only covers a week, so at the least you will have to reset it on a weekly basis.
The power supply is water resistant, but not water proof, meaning you can't throw it in the pool, and I would not recommend that it be left uncovered in a tropical downpour. My power supply stays outside 24/7, but it is mounted off the ground and under the eve of a roof, so it does not get soaking wet.. I have another one that is mounted on a fence, but inside a simple "box" that protects it from the rain and sun.
I have a Dolphin Premier, that came with a Caddy and a remote. I found that I never used either the remote or the caddy and that is why I replaced it with an S200. The Premier is about five years old and is now working in a rent house pool.
The caddy would be a great thing to have if I needed to move the robot inside a shed or my garage when not in use. It allows the power supply, the cable and the robot to all be moved together. Think of it as a simple two wheel dolly.
In my mind robots are for people that enjoy pool maintenance. If routine pool maintenance is more of a chore for you, then a water powered cleaner is probably a better option.
Thanks,
Jim R.