I don't think Gideon's departure hurt the show. (and in some ways it helped to show just how draining the job can be)

agreed. and i'm kind of glad that gideon just walked away instead of killing himself.

The writers did a good job handling the departure and in recasting another actor.

i like joe montegna and even though i don't love rossi, i do think he's a good addition to the cast. a breath of egotistical air, if you will. ;-P