My experience with older FEL's is that they are much better suited at moving dirt rather than digging. I have known folks dig a decent hole with the slip scoops, though.
X2 - I'll use my box blade at a high angle or a pond scoop to 'dig' - then use the loader to scoop the loose dirt.
Trying to dig with a standard FEL on a tractor is asking for trouble. They're not made for that.
Now a properly set up skid steer? Different story.
Digging in very hard dirt or clay is very hard on the loader and tractor. As long as the tractor only spends a small portion of its time doing that, it will probably hold up. But we have worn out and broken up no less than two farm loaders loading lots of lime and chicken/turkey litter before finally getting a commercial articulated loader.
What can really help a small tractor loader out is having something on the back that can loosen the dirt. A box blade with teeth that can be lowered can make a loader a lot more productive when in hard ground as well as save a lot of wear and tear on the loader. But any type of rear implement that is built stout enough to handle loosening hard dirt would work. Loosen it up, then get it with the loader. Same idea as having a ripper on the back of a dozer. I wish my dozer had a ripper.
