I don't know about a six string specifically. I guess it really depends on your style and what you wanna do.
We play a countryish style and the moment we got pick ups in our (admittedly fairly low cost) tenors it made the world of difference. More sustain; we cand hear the subtlties of solos better; we can adjust the ntome a skidge when we want more top of more fullness to the bottom end for particular songs.
I suspect if I had a top of the line instrument and the skill to play a complex finmger picking style I'd leave it and just m,ike it up but with my laminate Laniaki which I use to to thrash out country classics and pick a few solos - my undersaddle pick up is perfect.