GCRS / Hobbs device
I duno, you can put an awfully nice whinch on your truck for that kind of money. Spool out 60 feet of cable, attatch a port a wrap, and use that to lift branches up if need be. I have had good luck with that technique in the past. and then you have a whinch on your truck, which is really useful; tensioning highlines, getting unstuck, pulling trees over, lifting big logs and then driving a trailer under them, pulling small stumps etc.
also the capstan style devices have a real high learning curve, i dont even have enough time with most of my groundmen to show them how to use a port a wrap(i freelance alot and have no full time crew of my own). The GRCS is not a simple lowering device, and, at least with the Hobbs, if they wrap it wrong, the work is going to freefall, i've seen and heard about that happening. Bill, a friend of mine, was at a demonstration of the device where this happened.
another danger is that of the rope surging. a little slack in the line with a heavy load and the rope will surge foward a couple of feet. this is not dangerouse on its own, but the ground guys seem to constantly creep closer to the device, i always worry about their hands getting sucked in.
it is handy to be ably to walk that kind of mechanical advantage into a backyard, having may get you that kind of job over another company. are there many closed in backyards in your area? and do you have a steady groundcrew? if the answere to both of these questions is yes, i would consider buying one, but personally i'm not sold yet.
milemarker makes a 5 or 6 ton 2 speed whinch that runs off of your power steering pump, i think its about 1500 installed. havnt been shopping for one in 2 or 3 years so i'm not sure.
good luck whatever way you go.