Woodstock says that other than the occational click when the pumps start up again she hasn't had any real problems. I have heard however that they do not last as long on a wavemaker. Have you ever seen the Maxijet Mods? They are supposed to be the way to go for wavemakers, and powerheads that have good flow other than Tunze.
MJmods.com, Mod your Maxi jet into a high flow pump