I think it's a good idea to track your investment returns.XIRR works good, but I'm still not sure how useful this number is.
Yes, I can use this to benchmark against say the TSX. But there doesn't seem to be a TSX index that takes into account for dividend reinvestment... I think there's one for S&P500, but that's in US dollars. Gah, people with OCD should not be allowed near excel and financial data.