I think it works well. When my wife and used ours together and thought them broken until we learned about frequency disruption. And the water “leakage” from my mouth is somewhat messy.
Does a great job of cleaning your teeth. There was a learning curve though for me as I did a lot of spraying of myself and the bathroom until I figured out how to hold it correctly.
Would be an improvement if the brush heads had identifying markings or rings to distinguish between them. No protective plastic cover was included with the heads.