The gyres (Maxspect/Jabeo) and MP40s are my best current generators. They are relatively reliable, easy to maintain if done periodically, and capable of different modes (pulse, wave, controllers can link to other units, etc). The gyres can move a lot of water the length of the tank (6 foot) easily. I like the newer MP wet side design better. Follow the directions for cleaning will help with longevity and efficiency.