If you consider the RFM then I recommend you get a good one unless your grass is a LAWN "smooth".
I bought a RFM some years ago for a some what rough "yard", not a lawn. The RFM was red with perfect welds that were almost invisible, well they were invisible. It was Red and I think was a Jolle?, Steve Barlow told me French made. It broke on me a few times and I told him he'd sold me a piece of junk. He told me he would give me what I paid for it toward a great RFM, a Landpride. He said I wanted cheap and that's what he sold me and he was right. I think the Cheap one was around $1250 and the 6' Landpride was around $1700. I paid the difference and we traded.
The Landpride was a Tank and you could see every weld on it and it was heavy with a capital H!

I used the RFM behind a
B7800 and a
L3240. When I'd reach the bottom of the hill and make my turn the Landpride would turn the
B7800 when it swung around to the downhill side. It didn't phase the
L3240 which was twice as heavy as the B. The mower swinging the tractor wasn't a problem since I knew it was going to do it. The Red pretty Jolle? deck was so light that it didn't do the swing thing.
I prefer a RFM for open mowing, hooking up to the tractor, unhooking from the tractor and servicing. I also prefer the rear discharge because my experience with three rear discharge decks are a better spread out cut grass instead of the piled up rows of the side discharge. I've had both types and that is/has been my experience. I also like being able to get up close to "stuff" with either side of the deck.