I am posting this review in hopes that other Polaris 360 users will find some useful information. The Polaris 360 is the model that does not use a booster pump. I have several friends that own the Polaris 280/380 models and they are generally pleased with their cleaners.
A few notes about my pool: It is an inground 20,000 gallon, oval, vinyl lined pool with a sand filter. It was built in 1980 by the previous owner. For some strange reason the pool was built without a conventional main drain. It's "drain" is located in the side of the pool in the shallow end about 2 foot from the bottom, it is located very near the skimmer. This arrangment causes lots of problems for me because once dirt or dead algae settles to the bottom of the deep end it is nearly impossible to stir it up enough for the pool pump to pick it up.
I have owned a Polaris 360 for around 9 years. From day one I was never completely satisfied with it's cleaning ability. In order to get enough water to the polaris I had to plug one of my returns each time I used the unit. Not really hard to do but it is a pain, especially after doing this for 9 years. I purchased the silt bag and I rebuilt the internals of the unit a couple of years ago and replaced the feed hose. This returned the unit to like new performance (mediocre). My biggest complaint with the polaris was that it would not pick up the very fine dust/pollen that for a while I mistaked for mustard algae. I tried the panty hose and cotton ball tricks and these did help but I never could get rid of my dust/pollen. Another complaint I had was that the feed hose nuts always leaked. I replaced the hose and nuts more than once but I could never get them to completely stop leaking. Also, at times the unit would not get itself unstuck. I replaced the back up valve and this did help, but it did not help for very long. Overall I would give the Polaris 360 a grade of C-.
I recently purchased a used Blue Diamond robotic from ebay. I was hopeful that it could remove the dust/pollen from my pool that I have been fighting for over a year now. Even if it worked I figured that it would take a few cycles for it to get the pool really clean. I threw it in the pool and watched it for a while (kind of fun to do). After it finished it's cycle I removed the unit and cleaned the filter and I was impressed with the amount of very fine dirt that it had picked up. I decided to let it run another cycle and then let my pool sit overnight and see if the dirt/pollen would return the next day, as it has for over a year. The next morning I checked the pool and was pleased to see for the first time in many months that there was no visible dust/pollen. Normally when I hand brush the pool I can see quite a bit of this fine material. But after two cycles with the Blue Diamond I am pleased to report that this problem is now gone. The only complaint I have with the Blue Diamond is that there is one area in my shallow end that it never seems to get to. Not sure why but it is no big deal since I can just get that area with my pool buster. My overall grade of the Blue Diamond is an A.
I just hope that the blue diamond will be reliable as it is efficient. Hope this helps someone out there with their decision making.