I bought the Circle RO two weeks ago and am pleasantly surprised. The installation instructions were clear, concise and easy to follow. After completing the installation and flushing procedures, I checked the TDS, pH and waste water. All parameters were well within Brondell's claims - waste water for the last 250ml of the tank fill was 650ml, the TDS went from 98 to 6 and the pH dropped one point. The tank, while not overly large, refills so fast it is not an issue. I would not hesitate to recommend this system and will update my review after it has been in operation for a few months.