dig a big hole and bury it, is the only other option.
the vermeer 6" chipper does ok on tops chokes a bit, but I rent one occasionally when full clean up is needed, out here we get mostly limbs though, the 12" proved to be less efficient partly because Hertz can't maintain anything or have something there when you reserved it.
burning it "slowly" takes less time then you might think, start a little circle of a fire, let it burn down then spend the day dragging brush to it, couple of friends/family and you can clear a 100' circle in a day while having fun, just be sure to paint a giant pentagram around it to keep the county off yer backs.
Only 3/4 of an acre? Then build a small fire that meets the law, and cut up and drag the tops. Invite people over for hot dogs. We've done that for eons around here. It isn't really that much work and all you need is a saw--even a pruning saw will do a lot and maybe some loppers. We call it "hand piling". Maybe you can even build a firepit in a hurry to make it more legalish.
My beef about deforestation is watching more and more acreage of working forest disappear when I drive west, into town. That's forest that won't be planted back, but will be leveled, and have homes built on it. What with that, and the fact that the public lands are getting more restrictions thrown on, the future is not looking all that great.
I've planted trees in my "backyard".
you could simply lop up the slash so it laid down on the ground and let it rot to keep the soil productive. 
