My experience has inclined me to buy the smallest possible tractor and weight it up as much as possible. Part of that experience goes back 18 years, when on our property in southern Indiana we had a pond dug. Had a great old excavator named Walt Taylor dig it, mostly with his little dozer. He noticed I had a Kubota and to my surprise was a real fan, had at least one he used at home and told me it was his brother who advertised in the paper that he tilled gardens with a "Kubota tractor and tiller."
Well, that pond ended up with a seam in the bottom and we bought a clay sealer that needed to be tilled in, so we hired Walt's brother. He arrived towing his outfit, big HD pickup and trailer and a little B series that was about 24 hp. I had a 2wd B series 21 hp at the time and was impressed because his was about the same size, though 4wd. Well, he tilled the heck out of that pond bottom and it stopped the leak.
When he came back to be paid he was towing his rig again but had a big bushhog on the tractor, said he was on his way to cut for someone. Now, I believe it was a six-footer--at least a foot over whatever the tractor was rated for---and I commented on it. He said the dealer told him it was too big but the tractor would handle it. He said he worked his tractor hard and used straight 50 weight oil. He also had cut the roll bar off because it hit limbs when bushhogging, which I thought was insane and still do. He had made a little shelf out of the rollbar at the height of the seat back.
I wondered why he didn't get a larger tractor. He said he didn't want to have to have brakes on his trailer and a bigger tractor would obligate him legally to do so because he'd go over whatever the cutoff was. I later got a 16 foot trailer with electric brakes and it was no big deal. I wonder if an old coot like that didn't consider electric brakes BRAKES and was talking about REAL surge brakes?
Anyway, I think of those brothers sometimes. Nice guys, good equipment operators, Bota fans, original characters. They gave me a lot of faith in small tractors to do big work, with care. Of course folks overload and can and do damage CUTs, but at least one old feller and his little bota made a big dent in Hoosier weeds and dirt for a while.
Because of my experiences, the constant refrain on these forums to get the biggest possible machine makes me shake my head. Small is beautiful. In know a guy who got a 30 hp+ Kubota for his few acres, a machine fit for 40 acres in the old days. It is beautifully equipped and just sits in his garage. It is too big to maneuver with a mower in his spaces. He uses it in winter for snow removal, and it's wonderful for that. I'd rather have a tractor that was optimum all year and fair at snow removal.