I always forget which is which, but the T-28 and T-31 are among my absolute favorites. I have three, all with the larger 79" drivers, and all in 17/64 scale.
I had a PSC here for some light maintenance, and I was less than impressed. If you want a mantel piece, then this one is for you. Try not to handle it very much, and do not expect it to run.
I have found that models with narrow fire boxes are best powered through the tender. Putting a motor in the boiler destroys the essence of the model.
All, of course, opinion.