4C Update after 2 weeks.
Tyre pressures (PS4S rear, PS4 front!) were way off - rears were the correct 29, but the fronts were on 32

instead of 26. Now dropped, not made a massive difference to feel but it definately softened the ride, especially hitting ruts. Now I've had a chance to take it down some twistier stuff and it does get thrown off-line
way more than the Elise/Exige ever did. While they brushed minor undulations off, you constantly need two hands on the wheel with the 4C. It's busy....if this is 'fixed' it must have been pretty awful out of the box. Can things like that be improved any further? I'm not educated enough to know if things like geometry and damping will have enough of an impact or issues like this are deeper engineered.
Either way, that plus the boosty nature means you don't get the kind of confidence you'd have in an Elise to really push....not that I do really these days, but still, it can be nervy despite massive grip levels. Otherwise, it's seriously quick to the ton and feels like a properly special, mad little thing

...although mega paranoia about where it's parked mainly due to it's width so it won't fit in regular spaces if you want any chance of getting out.