I've gone back and forth on getting an excavator. My neighbor has hired people to work on his place with everything from 8 tones to 45 tones. The 8 ton machine seems to be pretty good at taking down trees and digging stumps, but he had a 15 ton machine there for a very long time, and it got a lot done, a lot faster. But when he decided to buy something, he talked to me about my backhoe, and decided that it was a lot more useful then an excavator.
For me, I have a simple 2 wheel drive, open station backhoe that I can take any sized tree out, cut it to size, and carry it with the grapple on the loader. I can haul a yard of dirt at a time, and it's great for back dragging an area to smooth it out. Having tires instead of tracks means it gets around faster without tearing up the ground.
The biggest negative that I have in getting an excavator is that it's terrible and moving material around. Once you dig up the tree, it sits there while you get something else to pick up the tree and haul it to the burn pile, or cut it into firwood. Once you dig the hole in the ground, you need something else to move the dirt to where you need it. There is nothing better at digging then an excavator, but there is also nothing worse at moving stuff around then an excavator. When my backhoe wears out, I'll but another one. Odds are very good that I'll never buy an excavator, even though I'd love to have one.
And I just thought of another great use for the backhoe. It's fantastic at pulling my other tractors and mowers out of the mud. Just connect a chain to the hoe bucket, and pull. Being able to drive the backhoe to where I'm stuck as fast as possible makes the entire process less painful.