Thanks for the detailed review.
F-holes in the violin family instruments are there to make the area of the top around the bridge more flexible and consequently the sound has more high frequencies. But with a center block, I'm not sure if it matters that much. And the Guild obviously has a block.
IME, f-hole Höfner basses (like my Senator and 500/3) don't sound less fat and bassy compared to closed hollowbodies like the Beatle bass or 500/2 (the German-made ones without center blocks). If anything, they have more lows.
I agree to a point Ilan. I think a lot has to do with the variables of wood resonance, pickup quality and freq response, block or not, etc. I had the Senator RI and it was just plain dull, no life to it really. I didn't keep it. My Gibson EB 650 has a block, f-holes, maple body/neck, and TB pups. It sounds like a rip roaring solid body T-Bird. The variables are right in that case.
Interestingly, I can't find the right setting for my Hofner Club bass and the Mesa rig. It's all boom and mush. I'm still working on it, but it so far doesn't work well with the all tube Mesa.