What's the general assistance with when you use CAST versus CONVERT? Can there be any performance the process of selecting one versus another? Is a nearer to ANSI-SQL?

CONVERT is SQL Server specific, CAST is ANSI.

CONVERT is much more flexible for the reason that you are able to format dates etc. Apart from that, they're virtually exactly the same. If you do not worry about the extended features, use CAST.

Convert includes a style parameter for date to string conversions.

http://msdn.microsoft.com/en-us/library/ms187928.aspx

Cast is ansi, convert isn't.