Giant Maso Mastiffs- Anyone have an experience with Thunderheart breeders?

Hey guys, I have never used Yahoo Answers before, so I accidentally got my question I posted earlier deleted because I responded to the answers, whoops! Haha, I didn't realize that I wasn't supposed to do that. So sorry! Anyway, I am very interested in getting a large dog for my family, one that is good with kids, has a low-medium energy level, and has good health. I am aware of the controversies surrounding irresponsible dog breeding and puppy mills, as well as "mutts" (mixes/hybrids/developing breeds.) What I like about Thunderheart breeders, is that they seem to really care about how the dogs are taken care of, you have to sign detailed contracts upon purchase saying that you will feed the dogs GOOD food, and basically take excellent care of them. You cannot just dump them, you have to return them to the breeder if at any point you are unable to care for them. Also, I don't mind having a mutt haha, and I like the idea of a mostly old english mastiff that has is leaner and has better health like a Cane Corso. My question is, I would REALLY love to hear what people's personal experiences have been with this breeder/these dogs, so far everything I have heard from people with personal experience has been very pleasant, and everything from people without personal experience has been very negative. I would just like to get as much information as I can. Thanks!!