Difficult to answer that question. You'll have to experiment with different types of images to see what works.
In general terms, film has the advantage of providing more resolution than digital because there's no precise cut-off. It just keeps on, providing more and more resolution at increasingly irrelevant contrast ratios till it reaches invisibility at about 2% MTF
Digital, on the other hand, does have a precise cut-off point. But it has the advantage of providing, perhaps, a higher contrast at resolutions lower (but more relevant) than the film cut-off point.
There's a whole lot of basic maths that deals with the relationships between resolution on sensor, resolution on enlarged print, and perceived resolution of print in relation to viewing distance from print. BJL is an absolute whiz on this sort of thing
I would say generally, a 20x24" print from a 10D can
look spectacular, provided you've used your best lenses and have abided by all the accepted rules for attaining sharp images.