The other big differentiator is the memory. The DOS card in question has 32 MB of dedicated RAM; whereas running VPC it has to steal system RAM. Yes, you could in theory allocate more than 32 MB of the system's 72MB total; but the real physical RAM on a real physical CPU will run it better.

If you want, I'll find some old Windows 95-era benchmarks, and run them both on a 486/100 DOS card and in Virtual PC...