This topic has been discussed in a half dozen threads and a quick use of the search feature brings up pages of info about props and the MT props.
I can only repeat myself again, I have 14 years with my MT's and no regrets. Once I figured out how to keep the FOD out of the rear things have been Peachy.
I know that if you plan to do a lot of unimproved runway takeoffs the odds are you may encounter more issues with these blades but they are very easily repaired. Some folks gave up on them and that is understandable. You do have to buy both front and rear at the same time. No spreading out the cost over the years.
Robert, your C model is approved on the list
http://www.337skymaster.com/messages...highlight=prop
http://www.337skymaster.com/messages...highlight=prop