This is a really interesting topic!
Just a quick thought if you don’t mind? I know this might seem a little long winded but please bear with me 
I remember a column from Model Railroader by Tony Koester on his Nickel Plate multi-deck layout that is often featured in the pages of the magazine. I forget now the exact wording but it was along the lines of what is “good enough?” I think the point he was making is that his layout is obviously very large, and to get it up and running he had to everything to a certain standard to start his regular operating sessions. He thus needed to get projects completed, and his comment was that he couldn’t justify spending weeks super-detailing a plain-jane 40’ boxcar when there were so many other projects like scenery etc to complete. Instead he offered up the idea of blanket standard of modelling, one which he felt was “good enough for now.” For example that could mean that the bulk of his rolling stock received proper couplers and weathering, but were not necessarily super-detailed to a museum display level. This would then allow him to work en masse to build his boxcars etc up to a standard which he felt was pleasing to the eye and “good enough,” also leaving enough time for all the other things that he needed to finish up. I think he also continued to suggest that he would go back and revisit and raise this overall standard, improving, tweaking and re-doing, but the concept remained that everything was to a singular, or at least similar, standard all round.
I quite liked this philosophy! For me, it meant trying to prioritise my limited time and to aim to try to complete projects, so that ultimately I can make running models and can include those on our own operating sessions. I only say this because I am 100% with Craig here, I struggle to accept my own limitations and I really am WAY too picky about things!
I guess what I am saying here is that for our line, the Somerville & St. Francis River, I like to pick a challenging but achievable standard, and work towards that. This means that I can enjoy the challenge, but at the same time complete projects and get stock out into the garden rather than trapped on a shelf. It doesn’t however mean that I am limited by that standard though, like Kevin S mentions above. I continually go back to older models and improve or add new detail to try to always raise the overall standard of our line. For example, I am now systematically returning to old ready-to-run aristo boxcars and adding brake hoses and coupler lift bars to help improve their detail. I think in the end, I don’t want to have one beautifully built, 100% rivet accurate locomotive, which I can’t run because my track is so poor or I haven’t yet built a railroad to run it on! I mean please don’t get me wrong as I really aspire to the level of detail that Craig refers to, that is my bench mark as well, but I also try to ground that idea within the context of our whole line, and all the tasks that are required to maintain it and keep it running smoothly.
Tony’s ideas made a lot of sense to me and I hope others can find it useful too?
Best wishes,
G
