Speed, too. You run into some pretty hairy Excel constructs, and the Excel team's optimizations really pay off.
It's been a number of years, but I used to spend a good part of my days in Excel. It has its own quirks -- may its inaccessible underlying formatting constructs be damned [1] -- but hey, can that sucker eat spaghetti (code -- so to speak).
(BTW, it may help to understand that many financial constructions are politically driven and otherwise idiosyncratic, to the point where you will never be able to code them up in a formal, regularized, and consistent construct. The "pointy haired boss" (whichever one, on whatever day) is always having you either insert or compensate for another "x factor".)
[1] As one, but not the only, example, try formatting 999D9 as text with leading zeros, some time. You'll find an odd result you eventually realize is the value with D9 expanded as an exponent. Like Fortran (so I was eventually told while mentioning this behavior -- never used the language, myself), Excel treats not just "E" but also "D" as demarcating an exponent. (Besides, you're formatting as "text", so why is it interpreting the end as an exponent? Although I can see where the leading zeros specification may throw it into a different mode.)
It's been a number of years, but I used to spend a good part of my days in Excel. It has its own quirks -- may its inaccessible underlying formatting constructs be damned [1] -- but hey, can that sucker eat spaghetti (code -- so to speak).
(BTW, it may help to understand that many financial constructions are politically driven and otherwise idiosyncratic, to the point where you will never be able to code them up in a formal, regularized, and consistent construct. The "pointy haired boss" (whichever one, on whatever day) is always having you either insert or compensate for another "x factor".)
[1] As one, but not the only, example, try formatting 999D9 as text with leading zeros, some time. You'll find an odd result you eventually realize is the value with D9 expanded as an exponent. Like Fortran (so I was eventually told while mentioning this behavior -- never used the language, myself), Excel treats not just "E" but also "D" as demarcating an exponent. (Besides, you're formatting as "text", so why is it interpreting the end as an exponent? Although I can see where the leading zeros specification may throw it into a different mode.)