I would agree that what you describe is probably the best for pod survival, however I have my tank set up in the living room of our house as a main feature and I enjoy the very clean look of the set up that I have. So a refugium above the tank isn't an option for me and I don't have room behind for a hang on on either. It needs to be above or in the sump.

I didn't have a power head. It was directly under the overflow pipe so whilst it was a small ball it would tumble in the flow of the overflow pipe.

When it got larger I would just try and remember to turn it over every once in a while.

I'm in the process of planning out a low flow 20 gallon refugium that will gravity feed to the display. I agree with BCOrchid the above the tank refugiums have far more benefit then an in sump or below tank version. No chopped up pods, no risk of overflowing or power failure or anything else. That said it obviously isn't practical for everyone, since it can be an eyesore. I'm lucky enough to have my tank against the basement stairs, so plenty of space behind the wall for gravity fed fuge, sump, and ATO.
I have seen some nicely designed fuges hiden in boxes on the wall or behind fake books and such.