Nice scene Eoin

Classic buildup, but well done. I like these little details like a small patch of cloud here and there.
If it were up to me I'd improve just one part of the image and that would be the lighting. On my monitor it is very dark, mainly around the trees.
I think this one could either use improved GI settings, use 2/2 or if you already did use 2/4 and/or with an AO enviro light added set to 0 for atmo and somewhere around 0.25-0.5 for surfaces.
Looking forward to see your next one

Cheers,
Martin