Are you hearing or feeling a big difference , i am away from the Axe at the moment
And was curious to what tonal changes people are experiencing
Are they subtle or pretty noticeable
Yes, it's sorta subtle, but worth it.
When I selected the 4x12 Bassuy impedance curve along with the Bassguy amp and its normal cabinet as a test earlier, it felt more 3 dimensional on my ears, if that makes any sense at all. It also seems to affect the eq in a subtle way. Some curves felt open, whilst others felt more 'pinched' and in focus in the mid-range.
The only way is to try it for yourself later and see what you think as tone's all subjective.