TBH, I hadn't used my Portamento SRF705 in a live situation that much before I got the Aerium SRH505. I think I had only brought it on stage three times, although I used it in band practices a lot more. Then I got the Aerium, which instantly became my gigging bass. Of course, the Portamento has 3 pickups whereas the Aerium only has the piezo. But what I think the most important part that differentiates the Aerium sound is the combination of the piezo pickup with a semi-hollow body which able to produce a warm and woody tone that I really like (which I felt that was missing from the Portamento). Yes, the Portamento has three pickups, with three vol knobs. But you need not to worry so much about these. Personally, I prefer a bass with a master vol knob. But, my first bass in the 80s was a PJ, which had 2 vol knobs, and then my 2nd one which became the only bass that I had owned for ±22 years starting early 90s, was a J bass, which also had 2 vol knobs. So, I can bare a bass without master vol knob. Regarding how I would use the three vol knobs, it's purely situational. Mostly I started with the piezo, then add the magnetics. But in studio practices or when I gigged with it, I've never used all three pickups at the same time, either neck with piezo or bridge with piezo. I think there were also times I used only either one or both magnetics, without the piezo. Again, it was all situational. Depends on how I would like the bass sound to sit in the band mix. But TBH, I haven't really enjoyed the piezo so much until I got the Aerium, which I think none other than because of the combination with semi-hollow body thing. But referring back to your opening post, particularly that you would like it to be funk-ish sounding, I think the Portamento would suit you better than the aerium.