johnnyringo,
I've enjoyed reading this thread and maybe can add a little to it. I'm two years into a project clearing 70 acres of East Texas 7 year old growth clear-cut. I'd guess that 7 year old clear-cut East Texas is probably equal to 25 to 50 year old elsewhere because of our incredible tree growing conditions.
I'm running a Case 450C dozer for all the work. Most of the trees were/are about 6 to 8 inches diameter and I have little trouble pushing them down and into burn piles. The real difficulty for me are the old large stumps remaining from the previous clear-cut. Those stumps are really hard on my small equipment...in fact just this week one got caught up in a track and caused it to throw...not a fun repair job.
Time is a big variable in this kind of project...i.e. how big of a hurry one is in and how much time one is willing to spend on working it. I'm a little different, I suppose, but I enjoy doing the work myself. I now have about 35 of the 70 acres ready for liming, fertilizing and seeding this spring. The other 35 acres is mostly cleared but needs a lot of finishing work still. Should be completed by this fall. I'll be glad to finish, but will also be somewhat sad to see the project end. I have looked forward each day that I can work on it, to climbing on the dozer and getting after it.
I paid $13k for my small Case 450C. I've rennovated/dug two ponds with it in addition to this 70 acre project. I've gotten my money back many fold from just an economics standpoint, but have gained immeasurable satisfaction and joy accomplishing this myself. It isn't for everyone, but a project like yours can be a great blessing in terms of personal satisfaction for years to come.
Best of luck to you on whatever path you choose.