On every steam locomotive I've seen, the smoke from the stack just "seeps" rather than exit as a "blast" Very un-prototypical. I saw a Marklin locomotive that had steam blowout from the cylinders that looked pretty good, but lacked the volume of "steam" emitted. What progress has been made in making steam release and smoke "blast" more prototypical. I think some sort of bellows device could be devised to accurately "blast" smoke from the stack. That appears to be the last piece of realism that is lacking on locomotives. The smoke could also be more black. Something could be devised on larger scale locomotives due to more space available, but might be hard to do in HO. In other words, how far can we go with realism?