I've seen a lot of people use the COALESCE function in place of ISNULL. From internet searches, I've found that COALESCE is ANSI standard, so there is an advantage that we know what to expect when using it. However, ISNULL seems easier to read since it seems more clear what it's doing.
I also realize that ISNULL is kind of tricky since it acts differently on different database servers and in different languages.
All of that, in my mind, boils down to style and standards. Given that style is subjective, is there any reason to use COALESCE over ISNULL (or vice versa)? Specifically, is there a performance advantage of one over the other?