DirectCast For Casting Without Conversion

I usually avoid VB's built-in conversion functions (CStr, CDate, CBool, CInt, etc.) unless I need to do an actual conversion. If I'm just casting, say from an object to a string, I normally use either DirectCast or TryCast, under the assumption that CStr, etc., are doing some extra stuff I don't need. But sometimes the DirectCast syntax is a little cumbersome, as in the following example.[code]SqlDataReader.Item returns an Object, which needs to be cast to a String. CStr is easier to read, type, and explain (IMO). My question is, does it matter which one I use? Should I just go with CStr (and CDate and CBool, etc.) and not worry about the extra work I assume those functions are doing? Is there any other downside to using these functions?