I think I prefer the SOOC colour one, despite really loving black and white in general. The light on the sea is much better in colour, and the castle itself is easier to distinguish from the clouds. From that angle, the castle tends to look a bit like a row of houses, in silhouette! I like the shutter speeds you've used for the main pic (not the long exposure one), as there is a strong feeling of roiling sea (and I particularly like the way the spray top right is above the horizon). I also like the way my eye is attracted first to the rock front centre, then up to the left, and then bang, there's the castle!
Is it a 4:3 crop? Wondering if shrinking it sideways a fraction (say 5:4) might help.
I know (roughly) the spot you've taken it from, had a couple of goes myself from there but not yet very successfully. It's a difficult castle to get a really strong shot of, despite being so dramatic! There's a spot low down on the other side of the castle that I want to get back to when the light and tides are favourable.