Leonard,
I think you might have it backwards??? Most ppl I know started out w/ downdraft skimmers, but then retrofitted them w/ becketts. I know Sanjay did that for one.
At the flow rates we are concerned w/ the beckett will entrain more air than a mazzei. Mazzei's are made for REALLY high flow apps, like pond aeration, etc. Becketts perform better at low flow, but like higher pressures, as frank mentioned above.
Cheers
James
ps, hopefully that first sentence doesn't look like a flame. It's not meant as one.