I am using mine with a Bach 5B and it certainly improves the slotting and tone

There is not too much Mass on the booster, so I still have rich overtones, coupled with a very robust sound!- slotting is even more secure

I usually stick away from things like this because they usually don't work, but my slotting, tone, and intonation all feel great

I feel like the slots are more defined and easier to target