Hm, considering your location, cool grey, rainy UK, I think I'd choose the north facing window for this time of year, say May through September, then move it to the west-facing window for the fall/winter and early spring months.
Do keep an eye on it when it's in that west window though for the direct sunlight hitting it. Maybe you have another plant or a sheer curtain or something else that would give just a little shade in the spring and fall. In wintertime, I doubt your sunniest day would burn the leaves.
The west window would be excellent year 'round if it had something like an adjustable louvered shade on it so you could control the amount of light easily.
