Rich …
I use a set on my 6’ finish mower… This is my second set.
The first set was not very good, I contacted the guy that makes them. He checked & found there was a mistake made drilling the first.
He sent me a second set. With that set I discovered the 12 blades had so much lift, the air blowing under the deck tended to push the grass down, this resulted in a rather uneven cut.
With some experimenting I found that by replacing every other blade with a flat (no lift) blade, disk mower blades. Cuts and mulches very well.
It is a heavier load on the engine… mulching after all is re-cutting the grass. I probably do the majority of my mowing with the original manufactures blade.
MegMo is a solid company and he will try to resolve any problems. Seems some decks will handle the double air flow better than others. KennyV.