Hey Gary, my dad bought a Komatsu D20P (I don't know what the "P" stands for). At first I was dissapointed because it doesn't do much on hard dry soil. Then he bought an old D6.
Our dirt is about as hard as it gets but after it finally rained, the little machine did some work. I also learned how to work it better. Like Meadowlark said, its easy to haul and everybody wants to borrow it.
The D20P has a tilt blade so it works good on small cedar, ok on pretty big cedar and I've even knocked out some really big ones. The soil you have will make a lot of difference. Get one with an angle blade.
It also has pyramid pads for tracks so it worked good cleaning out a small pond. If I can walk on the mud it can walk on it too.
For digging a large pond, I couldn't have done it without the D6. I just finished the dam for a 1+ acre pond. I would push the first dirt out of the way with the D6 and then when I found clay/gravel mix that I wanted roads I would jump on the D20 and push up piles to be picked up by the loader.
All in all, the D20 is so versatile with the angle blade and pyramid tracks that I have plans for it lined up for a long time--if I can keep it from throwing the left track when I back up.