I have a JD 425 with a 54" deck. Got it with the mulching kit installed. I used it for about 5 years. Then I took it off. Never liked the cut it gave and the deck will choke and regurgitate big piles when the grass is heavy and/or wet. Tractor never stalled, as you know, they are quite powerful. The one piece of the kit that is nice is the rubber shroud that goes around the front of the mower deck. Makes the vacuum effect more useful. But, I say don't waste your money on the whole kit.
However, if you have a lot of leaves and don't want to rake or vacuum, the mulching kit is good for that. A couple of passes and the leaves are finally pulverized.
Too bad mine is too small for you, I'd just about give it away just to get the parts out of my barn.