George - The work method you describe is what I do. I use Ilford MG VI RC to develop the image and "recipe" for the final print, recording everything, often split filter printing to achieve the results I'm looking for. I use Ilford filters also.
I spent many years with graded paper, and shared your reaction to the 70's RC papers, but today's Ilford RC is nice paper. I wouldn't use it for exhibition, but the convenience of short wash, etc is great for exploring an image.
I find that when I move to final prints on fiber, the recipe (balance/proportion of hard and soft filtration) is very close to the original 8x10 RC print. Usually I am scaling up, so the relative speed of the RC to the fiber is not important. However, when I use a scaling up guide to estimate the exposure for the larger fiber print, it's usually very close. I don't think the papers vary in speed any more than one emulsion batch to another. I always test first anyway, bracketing exposure from what I think it will be.
I highly recommend the Ilford papers. I miss Forte fiber paper, it had a beautiful tonality when selenium toned, but over time, I think the Ilford papers are more consistent.
If I remember correctly, the 23C has a filter drawer, try the filters. It takes longer to work up an image from scratch, but the control is much better with split printing, and even with single filter grading, I don't think you will find the paper to be lacking in quality compared to graded papers.
Another George