Since this question is in regards to a Massey Ferguson GC 2410 (2310 or 2610 would be the same) I will share my experience.
In the backhoe manual the instructions state to run the engine at 1500 RPM while learning to run the backhoe. After you get better on the hoe more RPM equates to faster cylinder travel. But the majority of the time I find my engine is running 1500-2000 RPM with the hoe, I don't think I have ever used the hoe at over about 2000 RPM. The hoe seems like there is plenty of power available at all engine speeds but you can move more cylinders simultaneously at 1800-2000 or so RPM than 1500.
I find the loader lifts a heaping full bucket of dirt best at about 2000 RPM, but then I lower the RPM to 1500 or so to transport the load.
But I really appreciate how quiet the GC 2410 engine is when operating at 1500-1800 RPM. Quiet and a good amount of power available, plus your hour meter moves slower at 1500 than PTO speed.
Bruce