this preamp-pickup combo is designed to compete with K&K's rockabilly rig (which I previously used, so this review will mostly be a comparison).. and it is better in some ways, worse in others. There is a noticeably better range across the EQ and gain pots (which are located usefully on the outside of the unit, unlike K&K who took the bewildering decision to bury the gain pots behind the front face of the preamp where they cannot be adjusted without a great deal of hassle).. Sound-wise it is bright and lively, with plenty of output. The bridge pickup will function as a stand-alone pickup for those well-paid jazz gigs we all fool ourselves we're gonna get :)
The only downside is the finish and durability of the 'externals'.
These are sub-par.
For example, they give you a fingerboard ('clicky') pickup which does not have enough wire attached to reach the part of the fingerboard where it needs to be!! ... and my bass is just a 3/4 so FORGET putting one of these on a 4/4 bass.. The wires are cheap looking and thin, the sockets are plasticky and less reinforced than the K&K, and they look like they will give trouble sooner rather than later.
However, for the price this represents a good value, easy and convenient way to make a rockabilly sound.
Put it on carefully and permanently and it shouldn't let you down.