I'll go out on a limb here, and give my own positive experience with powersweeps. I use the prefilters, so maybe that's helping. The corals like the extra water movement. If I had more money, I probably would have bought Sea Swirls, but I didn't and still don't! I only have a 75 gal, so maybe they'll be ok?? You think? :?: I hope I didn't waste my money, but only time will tell.
Anyway, they are helping to eliminate dead spots, helping fight algae problems, and the corals love them. The sweeping motion that most wavemaker powerheads have is closer (than regular maxijets) to natural conditions. That's really the point of wavemakers in general. Save up for something better if you can, but if not, powersweeps seem (to me) to be an ok intermediate step.
Sara