Yeah, this is why it took me a while to get started with it! I was trying to A/B it on/off at unity but because of the gain on the mix knob, that’s almost impossible. In the end I had to drop the input gain on my amp and do it by ear.
The easiest way to hear the difference, for me at least, was to play over a backing track and see how well the bass sits. The LA-2A gives me just enough boost to avoid needing to really dig in during heavier passages, but not so much that string noises (sliding, clanking etc.) are noticeable.