i wear the same size in CPs and MMM side zips (40) though it's arguable I need to size up in both to my gap size (41) for maximal comfort. Definitely not uncomfortable though.
(this may not apply to your situation because of the tapering effect etc)
I have the one from SNS Herning. Actually wearing right now even.
I highly recommend it. It is a true slim fit and has pretty long body and arms. It will shape to your body in a magnificent way.
I'm usually in between M or L since I'm tall but slim and I bought it in size L. Was a bit tight over the chest at first but has now stretched out to be the best fitting piece of clothing I have.
I absolutely love it and wear it pretty much every day.