I still don't have a flail mower, but I am getting ready to pull the trigger on one so I am doing the research again to make sure I am not missing anything.
I had a logger come in an heavily thin 2-3 acres around the house. He also used his harvester to remove a LOT of brush. I got paid for the logs and got the brush removal for free - what he did with his harvester in a couple of days would have taken me months to do. I still need to come in with a dozer and flatten out a lot of ruts and holes now, and I need to burn the slash piles, but it was worth it. Property looks a lot better and I got some firewood out of the deal too (mostly maple, some alder and fir that was too short/split/crooked to use for lumber). Right now I am concentrating on getting the firewood cut up and stacked.
I still need to do some brush clearing, especially around the shop, and the brambles below the house. If/when I get a dozer in I will probably do some more clearing on one side of the house where there is a lot of small diameter maple.
So I still need the flail mower, and I will need to keep the thinned areas under control - they are already starting to grow back quickly.