If you calibrate your monitor and have a good one, what you see on screen should be what comes out in a C-type print. I can upload images to my printers without a test pint knowing it will come out perfect, but I still do tests with new images to be sure.
I do use a calibrated screen, but to me soft-proofing helps does not take me all the way. With more experience I would surely be better to predict the result though. What often happens is that the impact of subtle relations between luminances, contrasts, colors become different on the print than on the screen, but when I compare the print and screen side by side I do see on screen what I see on print. It's just that in some cases what may seem like minor importance on screen can become major on print. In my latest print I had to adjust the white balance of a water reflection because it looked unnatural in the print in relation to the sky. I did see the same difference on screen, but on screen it did not look like a major issue.
But again this is a personal thing, some do lots of micro-tunings of their prints, some just print. What matters the most is always the picture content. It seems like you know what you're getting into and that's what matters.