This is just my opinion, some guys will disagree with me and thats ok. training pens are ok if the pup is only in there a short period of time. once the pup is tracking, i would get it out. I personally hate these pens. I believe it can get a pup started a little earlier, but it can also develope some bad habbits. Ive seen dogs come out of these pens that are mouthy because everywhere they go in the pen they can smell a rabbit. I think a guy is better off trapping some wild rabbits and letting the young dog get all riled up and let it go in front of it. after he chases it, I would not turn it loose in front any more, I would just turn it loose and let the dog find the track. for what it cost to put a dog in some of these pens, you can buy an old slow dog to get these young dogs going. I have put dogs in a pen before and I start them myself, and personally i can't see much difference. If you start it in the wild, it might take a little longer, but it shouldn't develope bad habbits as easily. Good luck to ya.