That's really the problem in that 25-45/50 HP range as an apples to apples comparison can become difficult given how widely the frame sizes/weight/capability can vary. For example: a
B2650 is almost light enough to be within the rated lifting capacity of an
L3560.
Granted I'm of the thought patter that identifying what needs to be done, and how long is acceptable to do the task is a major driver when looking at buying a tractor and then let that and the budget drive the tractor sizing decision.
For me personally at this point I don't think I'd go smaller in either HP or frame size/weight than my current
L3560 for my 2.75-ish acres. Almost all of it needs to be finish-mowed (occasionally twice a week), and there are a couple dozen large trees (mostly in the yard) that shed some pretty significant limbs from time to time, then add in the 5,000sq ft. garden... Of course, I'm not sure I'd go that much larger either since the capability increase doesn't seem to cover the price difference for what I needed - or do.
Well, at least not until jumping into full-up utility tractors (which is something I may add at some point).
There's just a whole lot of variability in personal needs and tractor capability when it comes to that HP range -- so it almost ends up being the case there's not really "a best", so much as there's a "best for you"