Gill jacket fit

bigflangesmallsprocket

I've just bought 2 jackets, a Gill Morph and Freedom. Despite being described as form-fitting, they do seem to come up on the baggy side. I purchased size small/36-38 (I'm aware that I'm on the small side of that, but still expected a slimmer fit) and am 36, so am considering getting changing for xs, but wondered if anyone knows if the arms are appreciably shorter? I'm 5'7 and the current arms length fit seems ok at the mo, with just a tad to spare as youd hope.