Sometimes acoustic just isn't loud enough. Pickups
vary in complexity from very simple to highly complex.
The best pickup is the one best suited to the needs
of the player.
On my flattops I have installed pickups from K&K,
LR Baggs, b-band, Pick Up the World, and others with
very good results.
On my archtops, I prefer the Kent Armstrong PAF with
12 adjustable pole pieces. This pickup provides a smooth,
warm tone and the ability to provide perfect balance
from a variety of string types.