Shin, I doubt you'd be wasting your money doing this, but most of the stuff they do can be done by a non smith.
I'm "tool-challenged" as Tim Allen would say. I still manage to do most of the mods myself, excluding things like triggers, chokes, cones and mounting peep sights.
One bennie of DIY, one learns the weapon better.
OTOH, if time is short and so on, I see little they do that is less than good. How needed it is can be debated, but not the quality.
Evception, that #$%^& keyed safety....