You surely know more about COBOL than I do, but what about decimal arithmetic? I mean if the problem domain requires arithmetic correctly rounded to thousandths, with the operands loaded from fixed text fields and the results stored in fixed text fields, COBOL gives you that directly in the language, and presumably on a relatively efficient form. I don't know if using instructions like 8086 DAA and AAA is a win on today's CPUs, but surely avoiding the sequence of long divisions to convert from binary to decimal is a win (if what you're doing between input and output is, like, an addition and a multiplication by 1.0575, or something). Are you thinking that maybe some C++ template Decimal class with some integer parameters is going to beat GnuCOBOL on an amd64?
I wish I could give you a good answer, but I really haven't dug deep into the pros of the language. If you see any review of this I'd love to read it as well.
