I have both kinds. Like the treadle Kubota, survive the twin pedal JD without any real problem except getting stuck in the chest with branches because I can't work the twin pedal as quickly. Wouldn't be a make or break item. JD had direct injection before Kubota and after being surprised how much my Kubota L5640 could suck down under max load I checked Rhine fuel consumption specs and found the Deere would have whupped the Kubota. Still I rarely see CUT drivers run hard enough to use much fuel. People brag about less than 1 gallon per hour fuel usage. Go to the manufacturer's numbers and they're running about 25% power. 7' tiller sounds large for the size tractor you want. In our soil my 7' King Kutter is all my L5740 can handle but our soil sucks and in SW MO you are probably talking cotton land type soil that almost tills itself.
The official documentation for his 7' tiller doesn't list PTO HP but the reseller he bought it from states that the PTO HP range is 25-50. The soil in central MO is pretty thick and heavy and full of clay. He runs the tiller with the 1700 rpm economy PTO setting on his 5083E and the tractor doesn't know it's back there. Granted a 5083E even at 1700 rpm probably still makes twice the PTO HP of the compact units I am looking at. The soil in SW MO is thin and full of gravel so likely even easier to till up.
I'll have to do some butt time to see if I prefer a treadle or a two-pedal control.