I have a number of Pioneers from MMH also, and my experience goes with the people who say they are friendly, good free rangers, etc. They didn't grow quite as fast/large as I hoped, but this may also be due to the amount of free ranging I let my chickens do. They have integrated very well into my flock, which is a variety of pure breeds and mixes. I plan to butcher all but the largest rooster, keep the hens and then hopefully the hens will be good layers. I wasn't planning to keep any of the roosters but all my Rhodebars were killed by a predator, and I have one rooster that looks a lot like my Rhodebars and has a good personality, so I'll keep him around just for color in the flock. It doesn't hurt that he is also the largest/fastest growing of the Pioneers. They are about 4 months old now.