I picked up 2 of the 6025 to replace my maxi jets in a 65 gallon. As of two weeks ago the larger models had not been shipped.
They are a little bit smaller than a Tennis ball, and the magnet mounts are great. The tunze is shaped like a ball, and fits into the bracket like a ball socket, so that it is easily adjustable up and down, and side to side.
One complaint is that when it snaps into the bracket, the outside caseing pops apart sometimes. Also be carefull removing the brackets from the cardboard, as there are little tabs that attach the bracket to the magnets, and these break easily. It is easily fixed, but not something you should have to worry about. Tunze claims that the tabs are made as strong as they could make them, but they are still fragile.
They push a little over 600 gallons per hour, which twice what the maxijets where doing. (I think that the next model up puts out about 1200 gph)They put out a nice even flow, especially in comparison to the stream put out by the maxijet. I have some SPS right in front of the tunze, it is not being blown over and has nice PE.
According to Tunze on RC, the smaller models can be "controlled" as long as they are in the off position for at least 15 minutes. The larger of the models is controlable. When i get around to reprograming my ACJR, I plan on having the alternate every 15 minutes.