After a bit of messing around with toe in I feel the system is getting there.
I'm now leaning towards the room/placement is likely the main cause for the issues I experience, that combined with the greater detail afforded by the new crossover, tweeter and using the correct cable for S/Pdif.
It seems moving around and messing with placement the sweet spot is just out of reach, something always has to give, overly bright, muddy mids or lack of bass extension.
I also pulled the networks and checked resistance values which are pretty much even across both.
I did however swap the networks which with a short listen seems to have brought about a bit more balance, I've been finding the right channel much more forward than left despite a rough check with phone db meter app telling me the opposite.
I'll have an extended listen later to see if its just an immediate feeling rather than an actual change