Well, I'm far from knowledgeable, in that department. A very close friend of mine, is an Arborist though, and treats, prunes, and cuts down trees of all kinds for the last 20-25 years. In the years, I've assisted him, on a few jobs. Generally, he would get one tree to the ground, and allow me to have at it, while he would work on another himself. I can tell you that the trees he set me up with were not quite 70 feet, (which is kind of a big tree). I remember a few close calls I had while cutting these things up. I was under his supervision some of the time, beu when he stepped away, a time or two I made a few mistrakes, which I almost regretted. I can tell you, simply based on these expreiences, that if you don't have experience, and don't have an experienced person working with you. You are better off, just paying someone who is a professional, to come in and do the job. You could get really hurt, very easily. It doesn't look very intimidating, or as dangerous as it is, but it is not as safe as it appears either. I remember a few times I cut a bransh, or large limb, and the whole thing either rolled towards me, or something brushed the back of my head, or flew up in my face, or swept my feet out from under me. I was taking my time, and studying each cut, before making it, and had a pretty good idea, or so I thought, of what each cuts result would be. I was also doing this work every day, for a summer for him, and only got better with practice. I'd pay someone to just get it done for you. They'll likely even chip the branches, and take the wood, of you find the right guy, and you don't need fire wood for yourself. Some guys will do it free, if they can have the wood, and chips, or give you a good discount. A cord of wood sells for some pretty good money, in Ct.