No.

What I mean by in-line SQL is the required functionality is implemented in the SELECT query itself.

Let say you want to format the date field somehow exotically.

Having it done in SELECT query (with whatever many CASE WHENs, CONVERTS and other SQL in-build functions), will perform faster than in CLR or UDF. Yes, using function looks more elegant.

Sometimes the desired functionality cannot be achieved in the SELECT and you will need to implement it as function, then, as I said before, CLR function will perform better than UDF.