Purchased my first Waterpik (rechargeable unit) when I had braces put on two years ago. It lasted 2 years before it would no longer charge. Definitely got my monies worth from it. Decided to try a smaller unit even though it was battery operated. Thought it wouldn't be as powerful as the chargeable unit. Was I wrong. This unit's stream is powerful and really helps in keeping my permanent retainers and whole mouth clean. I bring it from home to work and back again every single day. I think I need a second one :-) Nonetheless, I like the fact that when the batteries need replacing the unit slows down unlike the rechargeable unit where it just stops. At this point - unless I use my Waterpik before and after I brush - I don't feel like my mouth is clean. Love this unit!
I am so glad I saw this version of the Waterpik. I needed to purchase a unit, but wasn't really in need of the large original Waterpik. This smaller one is so easy to use. I can store it on the counter top when I'm done each day. I just open the door to the water compartment when I'm done to let it air out.