[Hybrid-Battery-Repair]

the car is more eager to assist, but also the battery accepts charge way more readily, as if the internal resistance were lower, (this may be the case, I don't know for fact).

That is exactly the "Better" in BetterBattery. The lower internal resistance results in a higher voltage under discharge and a lower voltage under charge, and that results in a more efficient charge and discharge and also higher maximum wattage to the electric motor and cooler running cells (at the same load).

Try it on a hill to see the largest difference from the stock battery - more power.

 

[Hybrid-Battery-Repair]

Couple more days in & I've noticed that SOC is raraely 100%, 80-85% is the highest I usually see, equally I'm noticing it rarely drops below 60% & whereas I used to get as recal the second I hit traffic, I've not had a single one yet.

Rarely isn't never. It's really hard to get a standard battery up to 20 bars - ever, but your BetterBattery will do it automatically on a long trip if you hold a steady throttle on level ground (and keep the speeds below 70 or so).

We've got insanely long straight roads here in the US (days of driving long), but you've got some long stretches as well. Keep an eye on the gauge next time you take a long trip.