Well I thought I was on the right track, I altered things to bring the image closer to the one above,
I thought it looked fine, but obviously still had many more things to alter.
Having bypassed the srgb utility node on all materials, and re-checking the AO was multiplied according to the new way of thinking
(not sure it's correct way of thinking) I found myself going back again & re-enabling them all(for some crazy reason)
I was in a place of predictable render result that looked ok to me.
I wrestled with many materials trying to get rid of spec dots that suddenly started appearing,
dont think I found the source(though as I edit the text I wonder if the sundial is the culprit),
and now after turning back on the srgb-linear(but rendering tone mapped)
the image is much darker and gone is the smoothness of the image(AA&Mat samples seem to low now).
Sorry for rambling on, I know nobody else who might be interested, infected with the Clarisse Bug.
As its now darker (render time doubled)the materials/spec /reflection is more prominent but because of the poor resolution look
I now have to figure out what needs to change, I wondered if i'd mixed my normal maps correctly
ie a mix of 2 materials has 2 normal maps, I have them going into a blend with mix/mask texture,
I decided to look into it, and found a tutorial splitting each to rgb and recombining, which looked handy to know about
but as I wasnt trying to have both combined in this way, I figure the way i've done it is a little easier & hopefully isnt causing any issues.
Just discovered the castle material i'd changed back to didnt have the srgb-linear, now i'm back to something perceptually better than before,
I've replaced the emissive bulb in the street, and positioned the sphere light to replace it, but I decided to flip them 180 thinking the throw would be better, didnt like the ies so trying the standard for a change...and so it goes on...
16aa & 16spp before was fine, though all light samples are on 1, not sure if having all samples on 1 only works with adaptive rendering,
and now it seems to be pulling back into shape with 8AA & 16spp. Ticking away the moments that make up a dull day.