I used to wonder about the relative merits of different large format systems. 8x10 is my regular format but I occasionally use 4x5 and rollfilm cameras. My practical testing shows:
Up to 8x10 final size rollfilm and 4x5 can deliver remarkably sharp results but the 4x5 is superior. But it takes a direct side-by-side to comparison to make this convincing. In practice well used rollfilm, on subjects that do not require camera movements, gives away very little to 4x5.
Photographs made by contact exposure with 4x5 and 8x10 negatives are of equivalent technical quality, just different (er, obviously) sizes. The 4x5 is too small for most subjects and the 8x10 is the minimum to deliver a sense of "presence".
An 8x10 enlargement from a 4x5 negative is awfully good but an 8x10 contact beats it visibly. In practice it is a comparison few photographers get to make. Either photograph is so good it could make the average digi-grapher's eyes fall out.
An 8x10 "enlargement" from an 8x10 negative made with a first class enlarger (Durst 184 for me) is not as good as the same photograph made by contact. The photograph made by projection shows fine white lines thinner than they should be and fine black lines thicker than expected. All this happens at the barely visible micro scale and is caused by image flare inevitable in even the best enlarger+lens combinations. Again this is a sharpness comparison only tech heads tend to make. The casual viewer without comparison photographs at hand sees none of this.