These 3PH tillers are heavy enough that they will ride the shoes regardless of being forward or reverse rotation.
My five-foot King Kutter II has never pushed any tractor I've had it on.
On yearly-used garden plots, one pass at 1/2 to 1 MPH is all it takes to make a great seed-bed. Thus the need for a tractor with good low gearing.
I've use it lot though on much tougher work. A few years ago I stopped spraying sod in the Fall (so it would break up during Spring plowing). Now, all the corn, potoatoes and pumpkins are planting organically. Our ground is miserable and full of rocks. When I plow up sod in the Spring, it's near impossible to break it up well enough for my corn planter to work well in. I can disk it ten times and it's still rough. So, I plow it and then run the King Kutter II tiller over several acres. It does a great job of breaking up all the sod clumps and making it great for planting. One pass at again . . . 1/2 to 1 MPH is all it takes.
I've only had one problem with the King Kutter and it happened when it was only a few days old. All the gearcase-cover bolts shook loose and started falling out. It's a design flaw. They used a gasket instead of RTV sealant - so the bolts cannot be tightened very much without crushing the gasket. To fix, you either eliminate the gasket- use RTV - and crank them tight . . . or . . . clean the bolts and holes and reinstall with Loctite, thus keeping the gasket just tight enough to seal.
My five-footer pretty much maxes out a 28-30 horse tractor with a 134 -144 cubic inch engine - so I would not want a five-foot counter-rotating tiller. Seems to me it must use more power, since it not only goes against the direction of travel - but it also pushes debris ahead of itself and "retills" it a bit. It does a little more work and therefore must use al little more power.