I started out cutting my place with a 6 foot rotary cutter. It does a fine job of cutting the grass, weeds and saplings, but not a great job. I'm happy with the results and would be happy to have just that alone, as I'm not too picky of how a field looks, as long as it's all pretty much one length. A day or two after I cut, there are lines of cut grass left behind, but they go away pretty quickly.
My biggest complaint about the rotary cutter for cutting grass is the dust it creates. If I cut an area with any exposed dirt on it at all, I'm eating dust. My latest thought is to cut an old tire to create a shield along the front of the mower deck to cut down on this. It's an idea that's building in my brain, so I'll probably do it sometime soon.
My next complaint is that on uneven terrain, I have to really pay attention to what's going on back there to avoid scalping or burying the blades in dirt. Lots of my land is pretty rough. I've taken out trees, filled in holes and moved on to other areas. When I cut down the weeds in those areas, it's very rough terrain.
This past spring, I bought a used finish mower. It's a little bigger then my rotary cutter, but not by much. They are both made by Land Pride, so this might be a fair comparison. The gear box on the finish mower is less then half the size of the one on the rotary cutter. The finish mower has three fixed blades, while the rotary cutter has two massive blades that spin around from the center.
They do a totally different job, but when just mowing grass, the finish mower is so much better at it then the rotary cutter that it's not even close. I can mow the same area much, much faster with the finish mower and have a much nicer result. The finish mower has wheels on all four corners, so it follows the contour of the ground. There is no weight on my lift arms as the attachment to the finish mower moves up and down. I keep the lift arms about the middle of this range of travel and never adjust them while mowing.
Since there is no weight on the lift arms, I'm able to mow when it's still wet outside and even closer to the shore of my lake without getting stuck. I'm also able to mow at a greater side angle faster and easier. It's really night and day the difference between the two.
My main two grass species are bahia and bermuda. Both are pretty tough on mower blades. When the grass is a foot or tall, it will bog down the rotary cutter. I've cut grass that tall with the finsh mower and it will also bog down if I go too fast. I just go slow enough to keep my RPM's up. I don't know how much is too much, but so far, I've cut everything I've wanted to with it. In those areas that it's really tall, I'll cut it twice to get a nice finish to it. The first cut leaves it a little ragged with some stalks coming back up. I just go over it again and get a beautiful finish.
My biggest complaint about the finish mower is that I get allot of flat tires on those wheels. I'm about done playing with tubes and fixing flats. The next time I get a flat tire, I'm replacing them with solid tires. I don't know where I'm buying them yet, but that will be my goal.
I also want to replace the blades with news ones as I think they are original. I don't know where the best place to do this is, or what type to buy. There seem to be serveral styles of blades out there, so I'll have to do some research on that. The blades just unbolt real simple and easy, so that part will be straight forward.
Changeing blades on a rotary cutter means getting a very large socket, an impact wrench powerful enough to take apart those bolts. On mine, the socket is 1 11/16 that are torqued down to 450lbs. It wasn't fun the fist time I had to do this!!!!!!!!!!!! Now I kind of got it figured out and can replace a set of blades in less then an hour, but that first time allot longer!!!!!!!!
Good luck,
Eddie