I have Linq calling Procs that do more complex things that a Proc as always done for me.
I write a Proc when I can see that it is the better thing to do for any of a number of reasons.
To me it's a clear case of "user the tool that fits the problem"
so if I nee to write a loop over a table and update some other table and I do not need per row data from the outside then that becomes a proc in SQL not in C#
if I see a bunch of inserts or updates that can all be done serverside w/o passing a ton of stuff that's a proc in SQL also.
if I have to go back and forth for things that sql does not know then I use C# in whatever form , classic sql commands, Linq or whatever fits the rest of the app.