Originally Posted by BrewBeemer
...Instead of hear say from members of this forum...
I would call it "experience" not "hearsay" -- that's highly valuable to me.
I think the consensus is that you can't position the input of the pump such that you create an air block in the tubing between your wort and the impeller. As long as the input doesn't point down, mine works fine in any position (albeit sometimes with a bit of fiddling). Oh, you also have to make sure that any air downstream of the pump can easily be pushed out, too (e.g., don't drop a recirc tube in liquid until the pump is primed and running).