RegEx.IsMatch() vs. String.ToUpper().Contains() performance

Question

Since there is no case insensitive string.Contains() (yet a case insensitive version of string.Equals() exists which baffles me, but I digress) in

Answer 1

I would expect RegEx.match to be slow based on personal experience with regular expression parsers in general. But as many folks have mentioned, profiling it is the best way to find out for sure. I've had to fix performance issues related to regular expression parsers, toLower and toUpper have never come back to bite me.