Kubota-Monkey,
Size or more important weight does matter, at least with tractors. There is no substitute for brute horsepower. When I was clearing this property for the first time, I was using a Belarus 530 with a Memo loader and a heavy 7' drag bush hog. If Ivan could knock it over the bush hog could chew it up. This place had not been mowed in years probably decades! The thickets I was easily mowing through would've stopped this L2500 Dinky-San /w3tcompact/icons/smile.gif in it's tracks. Welding a ball to the bucket to move the utility and horse trailers (both are goosenecks) was a great thing with Ivan. The weight of the utility trailer is just about par with Dinky-San /w3tcompact/icons/smile.gif. I was experimenting with it the other day and the trailer weighs enough to get Dinky-San /w3tcompact/icons/smile.gif on three wheels if it is off center or in a hole /w3tcompact/icons/frown.gif! However, this is the first year that I have been able to mow across the bottoms. If it wasn't a severe drought year, Ivan, who weighed in at 6000 lbs. dry, would go visit his commrades in China. I can park Dinky-San in the isle of the barn and ride by on a horse and not worry about bumping walls or tractor. No way with Ivan. That meant I had to dedicate one whole 12' stall and fence beyond that just for Ivan. I have an extra stall now.
The size and horsepower need to be matched somewhat to the jobs at hand or anticipated. My perfect tractor really falls somewhere between these two. My pastures are clear now so Dinky-San does just fine spinning a 5' three point bush hog and the price was right at a time when I needed it to be.