A 4449 is on my short list of model steam locos yet to buy....but I'm not preordering anything any more. I won't commit to buying a new one until I see and hear it first.
Also, on the running gear, can't they use most of the running gear from their 844 offering as a starting point to help make their model more accurate? The thin/small running gear doesn't cut it for me. The rods on their 844 have a nice, hefty look to them, IMHO.