I have a Bachtold 8hp/26" brush mower. I have cut brush taller than I am in one pass. Tall (waist high) thick grass can be cut in one pass as long as the blade is sharp. Bachtold used to make the 24" DR, and is a good machine. The DR has come down in price, but mine was still cheaper, (less than $1200) I recommend you get a lot of insurance for this type of work. The design of these mowers is such that they throw things easily. It's hard to see debris in grass or weeds this high, and the type of people who usually let a yard get this way usually leave things in it for you to hit. I have broken several things, and run over many others. No prize poodles yet

, but I'm trying. Also, if you plan to trim these yards also, I'd get a more powerful trimmer. I use a Husky 232L, but the big Shindy is good, so is the HD Echo. I'm using my old 5x10 trailer to set up a rig just for this type of mowing, so I don't need to load and unload twice every time I get a job.