Dolphin Pool Cleaner
I had my Dolphin for a little over two years. Basically it works pretty well. The internal sensor does a great job to make sure the robot does not spend too much time on the waterline. It changes direction randomly and in general does a good job cleaning. Cleaning the filter takes a little time but it does an excellent job picking up even very small particles and dirt.
It can get stuck sometimes when you forget toys on the pool ground. It never got stuck on any stairs or any other part of my pool.
It does a great job cleaning, but as all robots, their intelligence is limited and depending on the pool shape there will always be areas that get cleaned more than others. It was easy to redirect the Dolphin pulling the cable gently at the right time.
The real problem is the Dolphin is not designed to last very long. I had mine for less than three years and I'm on the third motor and it just stopped working again with the same problem, so it's time for the 4th motor! The first two replacements were under warranty so I was OK with it, but now it's out of warranty and the replacement would cost more than $500. Obviously I'm not happy about it, but reading the reviews on other brand robots they all seem to have problems.
Yes there are many positive reviews but they tend to be from people who just got their first robot and are still in the phase of excitement.
I also don't make my decision on where a company is based. The best product is my winner, good engineering should be rewarded.
Having said all that I'm really not sure what robot I should buy now. There doesn't seem to be a really good quality product out there.