Oddly enough, that Guild bridge setup, when augmented with brass saddles as shown, works exceptionally well with the Guild body. The coupling to the body's center block is substantial, and the neck joint on the beast is solid. So there's plenty of energy transfer from the bridge back into the neck, which accounts for much of the Starfire's basic woody, somewhat upright-sounding tone. And there's no lack of sustain. Putting a block in wouldn't gain anything in that department, and the Guild bridge actually has more adujstment range than the basic Alembic tune-o-matic.
The brass saddles improve definition and sustain (over the rosewood originals). Also the way the bridge contacts the front plate of the instrument gives good energy transfer to the top as well, which really lets the body chamber pump. Even with the lower f-hole obstructed by the shielding plate, and that side of the bout weighted down by the electronics, the body is very active in the tonal shaping.
Overall, it's quite a remarkable instrument, even before the Alembic mods. I certainly love mine, even without the Alembic pickups and full-bore electronics setup. (I did do a master volume and stereo output setup, and converted all the controls to Clarostats.)
nic