I had a 5 foot woods RD6000 RFM on the back of my
B2910 and was quite pleased with the cut. I think it did a better job than my yardman garden tractor.
If you go with the RFM get one as wide as possible if you need to cut close to things like a fence line.
If you need to cut around things, like my small pond, for example, the MMM would do a better job, as it follows the front wheels rather than going opposite to them.
My area was small enough that the RFM was not a good fit and I ended up trading it back to the dealer for a new Woods Rotary cutter.
I cried enough about things that the wife did not object to my buying a MMM with a
BX2200 attached to it.
One thing that is really nice is to have the mowing tractor sitting there waiting for you to use it, and not having to deal with taking off whatever is on the back of the larger tractor, putting the mower on, taking the mower back off and putting the implement that you need to use again back on.
I don't doubt at all that your 3130 will cut real well.
It is a tough call. Even if the mmm is off my BX, it is easier to put it back on and leave it on than it is to do three swaps on the larger tractor. And the mower is on as much as it is off, so things go that much quicker...
In the end, if it were me, and I could not have a great second tractor to mow with, I guess I would go the add the mower to the
L3130 route...
Another thought...you have the DT...the area that you mow...does it call for a lot of directional changes? Will you have to even more directional changes using the larger tractor, than you did with the lawn tractor, just because the larger tractor is much bigger?
This might be a reason to lean towards the lawn tractor...