I've used both the "el-cheapo's" and the high end Woods models. Unless you are hitting hidden objects, cutting fairly large saplings, or dragging the cutter over things it may get caught on, I'd just go with the cheapo one. I have one of each right now and almost always use the cheapo one. The only things I did to my cheapo (started life as a Wallace) model was to add a slip clutch in the PTO line, and I used 40' of 3/8" wall 2" square tubing and built a cage of sorts around the mower. I still have much less than a grand in it and I'll use it as a battering ram. I only watch out for things that may hurt my tractor. Other than that, if I can run over it, the cheapo rotary cutter has done it's job.
Even though the Woods came stronger to begin with, it isn't 1/10th as strong as the beefed up cheapo model I use. Also, with a fairly loose slip clutch, I've never had any gear box problems. Even with the shear bolts that the cheap ones come with, I don't think you'd have trouble as long as you stay with the grade 2 bolts. I just don't like to change them constantly. As a matter of fact, I have a neighbor who is likely going to buy my heavy duty Woods cutter for his mowing business.
The only problem you will have with the cheap rotary cutter is that you'll bend the deck up rather easily if you don't reinforce it. If you can reinforce it, or live with bending it back into shape ever so often, then you're set. If I were going to have to use it 40 hours a week plus and my income depended on it, I'd probably stay with the Woods, but otherwise I'm not missing it. Good luck!