It can be a dilemma alright. There is a certain attraction to keeping a shiny new plastic model just as it arrived in its box, untouched and pristine. However the colours of some of the plastics while accurate when the stock was new, can look rather 'toyish' if not even a little fisher price until they get some weathering. Weathering can be very subjective, and its all a matter of personal taste, personally I like light weathering so the model doesn't look like a new Tri-ang toy from the 1980s, but rather just a little used in traffic and the original bright colours toned down just enough to create the visual impression of respectfully aged like a fine wine. An example is the fine Murphy Model mk2d super train coaches. The bright orange roof visually screams, but a light weathering transforms them, especially as models we spend more time looking down at the roofs, whereas in real life we view most rolling stock from side on and rarely see roofs. Each on to their own preferences. Consider it this way, soiling a pristine model by weathering it sort of makes it unique and perhaps even more collectable. The first few times it is scary as hell, but worth it in the end. Suggest folks buy a few cheap rolling stock items at swop meets like Stillorgan or Bray (eg €5 old BR tri-ang or lIma coach) and experiment on them before laying a finger on a €50 Murphy model coach.