After I switched to a Maytronics robot (M500), I realized why the Kreepy Krauly could stay in the pool with its two hour every day run of that noisy, KW consuming booster pump (which also required that the main VS pump be at 2700 rpm or higher, so that two hours was a major KW consumer.) The reason I could leave it in the pool and clean it weekly was that IT DIDN'T PICK UP DIRT! The day I took it out and put in the M500, after the 2.5 hr default run time, it was full of fine grit, dirt, leaf particles and even loose tiny gravel from, I suspect, the pool finish. I still wonder why my pool builder didn't mention or suggest a robot. The M400/500/600 models have a third brush in the center, and I think that makes a difference. After three months, it still picks up stuff I never found in the Kreepy Krauly bag. I don't leave it in the pool, though. I have a set up with the storage caddy next to an electric outlet under cover on the back porch. After running it--I use the 3.5 hr program usually--I clean out the filters, hose down the whole thing top, bottom and inside, and store on the caddy, loosely rolling up the low voltage cable to hang over the caddy's handle. That process takes about ten minutes.
Digression: [I keep an outdoor furniture cover over the robot and caddy when not in use, as I live on a corner lot in Katy Texas and have already had chairs stolen from the front porch, so I don't want someone peeking over the fence to see what's there and seeing something they can resell. Fence gates always have padlocks on for safety and security, plus eight surveillance cameras on a DVR.]
Starting up the robot takes about two minutes to uncover the caddy, stretch out the cable, and sit the cleaner in the pool. I'm not familiar with other models of robot, but this one ostensibly cleans the water line, but I still do a quick walk around with the brush hitting the waterline tiles and a few inches down, mostly to splash some water up onto the tiles for the brush. Also, the M500 needs to be fully underwater to run, so it can't clean the surface of the sunshelf, which is therefore part of my precleaning brushing. All together from out the door to starting the cleaner is five or six minutes. I usually rinse or replace the skimmer socks at the same time. The M500 can be programmed to run on a schedule, which implies that it can be left in the pool. However, I respect the power of chlorine to destroy plastic and rubber as well as encourage rust and corrosion. I don't want an annual replacement of the robot to be an additional cost of pool ownership, so I clean, rinse, and dry store every other day.
I bought the M500 because of the third brush (the ability to "drive" the cleaner from the phone app is a cute and useless feature IMO) and because my wife gets upset when I "go cheap." Since the pool is her dream, I spare no expense of time or money for her pool. It has turned me into a clean water fanatic, though. We spent Labor Day weekend with family at a rental beach house on Galveston Island. I could not go into that disgusting Gulf of Mexico water (did find it interesting watching cars get stuck in the sand at the beach access road, though. 13 on Saturday alone with 15 minutes to two hours each for retrieval! One compact sedan got stuck. A Samaritan in a 4wd pickup came over to help, but as he was passing the sedan, his pickup truck slide sideways and stopped barely six inches from being a side by side crash. It took a second 4wd pickup from the other end of the almost crash, plus a dozen tattooed beach goers to pull the sedan out of harms way. Tense moments. I also observed over the weekend that common tow straps are apparently inadequate for pulling stuck cars out of sand, as I watched at least half a dozen tow straps break.)
