My Muratori does well in my very hard adobe clay soil. I went a little narrower than the BX because I wanted to concentrate the power in this hard soil. If your soil is better than clay, you'd probably do fine with a larger tiller. Like you, I don't want to use something larger than the manufacturer recommends in order not to overtax the hp from the PTO. Here's one thought though about tractor width and tiller width: With a rough cutter or such, the width difference isn't a big deal, BUT, if you have a tiller that's narrower than the tractor, when you try to till the next pass adjacent to the previous one, the tires are going to partly compact the soil you just loosened up (unless the unit is offset to the outside of one tire-but then you lose manuverability in very small spaces). How much of a problem that is for you in your type soil, only you can decide. Anyways, just a thought.