Instruct: Classify Amazon reviews into positive or negative sentiment
Query: WaterPik WP-70/WP-70W

I had to return my recent purchase due to a defect. I have used WaterPik Dental Water Jets for many, many years and typically have to replace every two or three years. I was disappointed to receive a defective product but began shopping locally for another dental water jet. I purchased the WaterPik Ultra, and I am pleased with the design, size and operation thus far. I just hope WaterPik can maintain quality of their products and that my current purchase will provide another two to three years of service.