I own 3 orchard tractor :
One 75 hp FIAT 4 x 4 (my main spraying tractor for years)
One 55 hp New Holland (2WD chores tractor)
One 85 Kubota M8540 Narrow. (the new kid in town)
The 55 NH does all the mowing but is challenge a bit with heavy jobs with the shredder (I have a Votex and a Kuhn). Also, you need counterweight in Front. Drop that clutch a little fast and you will the tractor pop a wheelie. Good choice of transmission ratio for all jobs 16 speeds
The Fiat is strong, durable, tough as nail with the exception of all things electrical. Also noisy as hell. It has a Alo loader that I hate : autolevelling is more a pain in the lower back that anything elsewhen trying to pick up apple bins. And you can't use both function of the loader together.
The Kubota is a lot newer (altough I bought it used with only 200 hours on it). The cab is very quiet roomy (no middle bump); engine is powerful; Transmission is very limited (8 speed). The roof is cheap thin plastic and will break apart if you hit a low brach (ask how I know). The hydraulic shuttle is a God sent if you plan to use a loader a lot. The front axle makes the wheels turn faster in sharp turns and that works well. The ride is harsh because it does not have radials.
The 50 HP tractors are borderline in my opinion. You quickly run out of power or weight. Ballast in rear tires makes a huge difference. Loader wise, make sure you like the geometry of your loader. The Alo does not roll back enought to pick up rock with a rock bucket. Look at loaders on backhoe to see the difference. I don't know why we can't have the same geometry on farm tractor...
Last but not least, I also own a compact Komatsu track excavator (old but strong). Don't bother with the backhoe on a tractor. They are too short, too weak, and in the worst case scenario, can break your transmission casing in half. Farm out that work....
Keep us informed!

7 acres in Oka (Québec)
Certified Organic Orchard
Sunrise, MacIntoch, Spartan, Cortland, Empire,
www.verger-bio.ca