Loren, Mark-------I recently got one of their 2-6-6-2's and it runs/performs just fine. I know you said the goat or camelback, but these 2-6-6-2's are fun to watch. This definately is not a yard engine and it sounds like that's what your really looking for.
I asked the same question, [ Mantua quality], awhile back when I was considering the one I have, and all the feedback I got was pretty positive. I don't believe the one with the twisted frame is typical of this manufacturer. The replacement will likely give years of trouble free service. --------------------John