I've got a 40" Woods "Estate Series" tiller. Chain drive, slip clutch.
At the time I got it, I was caught up in the Great American Pastime of the "Race to the Bottom" which refers to quality and price. I wanted to re-work some lawn areas, so I thought a little tiller that would fit behind my B21 (13.5 HP at the PTO) would be fine. This was the smallest width I could get. An over frugal moment to be sure...
About 6 seconds after I engaged the ground for the 1st time, the tiller "found" a burred brick from building construction. This dented the top rear square channel for the tiller, and put a bend in the gate. It was nice to get that 1st "ding" experience out of the way :laugh:.
It cost about $1200 new in 2000 when I got it. Shame on Woods for making a low cost tiller, but I guess calling it the "Estate Series" was the secret warning. It would be great for use behind a 500 or 700 series garden tractor for use with areas that had already been prepped to some degree. That would be areas with no hidden bricks or big rocks.
I've been beating the daylights out of it tilling up an old rail road ballast area used for access during construction of the house, and it's holding up OK. It's hard to tell if the "six second brick" just got a lucky cheap shot or not. The slip clutch is the key there. With the low HP of the B21, and (presumably) the fragile nature of its PTO, the tiller and tractor have been protected on many occasions. I have stalled the tractor out before (that was my clue to get with the program and tweak the slip clutch annually) and both survived.
I would not dare put this on the 4520 and shoot 50 HP to it, slip clutch or not.
So guess what, once again it comes down to what are you doing (virgin prep work, tilling up old railroad ballast, tiling your garden site) and what your tractor has going for it (13 vs. 50 HP).
The "doesn't cover the wheels" is OK since this is lawn prep work. I could offset it if it was a problem. For me, the savings on the implement, amount of use thus far and narrow width are an acceptable trade off.
In the "If I knew then what I know now" department, I'd definitely still go with the slip clutch. I'd go width of the tires on the tractor. Tractor PTO under 25HP I'd go chain, above I'd go gear. Just a gut feel. When comparing comparable units, the heavier one would be better. And finally, be aware of the "Race to the Bottom" problem, no matter how much the implement brochures try to justify it. Although that said, I'd rather have a narrow good tiller than a wide bad one, there's just too much stuff to pick up lurking under the ground.
I used to make fun of the various companies brochures where they had pictures of backhoes digging. My scoffing phrase was "Anyone can dig in loam." Well, I'd also say "Anyone can till in loam." Once again, what are you going to do and how often are you going to do it?
Oh my, I've written another book...
Pete