Incidently, I tested the "Mike C style" function with minimal variable dimensioning (basically a hybrid of what we were trying on the T-SQL side based on the Kevins' postings).

It results in a very long return new sqldecimal( ... ) line!

Average execution time over 30 iterations was slightly better than non-"minimal variable dimensioning" at 777.6 milliseconds.

Again, I'd rather have more maintainable code than such a subtle performance improvement but in some instances, that may not be a luxury!