If you have a LONG tank that is surrounded by cabinetry and you cannot use anything like a vortech or wavysea then it is definitely worth it, but they are big and ugly.
I have one that I love. Only downside is it's pretty space consuming so I tried to hide it behind some rocks which need to be stacked up high. You are required to place it on the sides of the tank. Tuning can be a bit of a pain as each tank dimension plus it's live rock needs a different to be tuned differently. The water creates so much waves that my tank actually vibrates a little. I also hear it decreases the life of the tank, anywhere from 15 years or so down to 10-12.