Well, I finally got my rear discharge RFM in at the dealer's and got it hooked up. A 60" Bush Hog with chain guard. The grass was a little higher than usual and I set out to give the mower a good test. It was nice not having to worry about shooting grass (or anything else that might have found its way into my yard) towards the neighbor's vehicles like with the side dis. It was nice not having to worry about shooting stuff towards my cellar windows when mowing along the house. It was nice not having the engine bog down once, even when backing it into some high, creek-bank grass.
It wasn't nice seeing all the clumps of grass that emerged from under the mower's deck as I glanced behind to see what kind of job it was doing.
People talk about the windrowing of a side dis., I mowed with the side chute up and found that the grass normally scattered or if it did windrow, it was easy to go over again if it bothered me too bad. I think that with the chain guard on the rear dis. the cut grass just spins around under the deck until the deck passes and then it is left behind in clumps wherever it falls. Maybe I need to try to mow when the grass is shorter and it won't be as noticeable.
As with anything, it has its good and bad points and this was just my first time using it.
Oh yeah, one BIG plus, the PTO has a push pin rather than the steel ring you had to pull back like the loaner Bush Hog mower I was using. Much less awkward. AND, the dealer is selling it to me at cost, which should save me about $500.

FWIW,
Fred