Fifty-odd years ago when I was a kid, my parents bought WaterPiks for me and my two brothers. Over the years mine got lost during moves for school and work and, frankly, I'd forgotten about it. A couple years ago, I started having problems with sore/bleeding gums and--no matter how often I brushed--my mouth always felt like the bottom of a birdcage. Then, I remembered my childhood WaterPik. Just in time for one of Amazon's sales! I ordered the Aquarius model, and have used it twice-daily for a week. Guess what? No more bleeding gums! And after every use, my mouth feels like it was cleaned by a dental hygienist. Love, love, love this thing, and it's super easy to use! After reading numerous reviews here, I have to say that it makes a low, vibrating noise when in use but it's not loud (I have hyper-sensitive hearing and can't bear loud noises). If your unit gets moldy, it's because you didn't take 30 seconds to empty the tank and drain the line after each use. Try adding a couple ounces of mouthwash into the water tank when you use it and--just like you can your coffee maker--once in a while run some white vinegar thru the tank followed by two tanks of clear water. It's not rocket science. Those who reported it "leaking" from the bottom of the cleaning tip probably just didn't have it seated correctly. It has to snap into place on the wand, but if you aren't paying attention and press the "release" button on the wand instead of the "on" button to start the water flowing then, yeah, it'll leak from the bottom. Just snap it back into place and give your Therapy Llama a break. Water going everywhere? Don't turn it on until the cleaning tip is in your mouth, and then keep your mouth closed around it like you're supposed to. Seriously folks, I used one of these when I was seven years old and didn't have any of these problems. Buy one. You'll love it. I'll never be without a WaterPik again!