I understand the criticisms of some 3-D prints, but I would add my voice in support of the loco bodies etc. produced by Bill Davies ('heraldcoupe'). They are crisp and almost lacking in any evidence that they are actually 3-D prints. He supplies them in a coat of grey primer and I really think that they can be mistaken for high quality plastic injection mouldings.
They look nice (very nice) here, and I certainly don't intend to critique things I'm not familiar with. But looking nice is not everything. This goes for my own prints as well (I sell printed kits, so I'm not suggesting they are not a good thing).
Resin prints are often a bit brittle and not always stable over time. Materials and processing matter. I've had prints for long enough now that I'm relatively happy that the best will have the longevity for me. I'm not so sure they'll be heirlooms to pass on though.
But model design is probably the biggest variable. Detail level, robustness, fit and use of separate (non printed parts) where appropriate. This is not a one size fits all answer as modeller's desires/expectations vary. It's also not new, the same arguments apply to kits in other media.
I'm merely suggesting that judgements not be made on the basis of the process used, but on the product itself.
