Honestly, to me, since Springfield discontinued all the Brazilian labor, the build quality on everything from the Mil-spec to the TRP seems the same. The higher up in the catalog you go the better the fit and finish is. If it's below a loaded, there will likely be some slide overhang at the back where it's not hand fitted, but it will function great.
The big reason why the Range Officer is a success: They're building them. If I go look at any of my distributors at work on any given day, Ranger Officers are in stock, followed by Mil-specs, but hardly any Loaded models, or TRPs.
I love everything about the Range Officer but the rear sight, so simply change that and you're good to go.
I love Springfield and have owned 4 of their 1911s, but they're not trying to be Kimber. If they had 50 different 1911s you could order from the Range Officer might not enjoy the popularity that it does. But, since they are a little more conservative on their 1911 catalog, it means you take what you can get and currently for the money the RO is the best bang for the buck.