I kopped the slim oxford in both M and L to compare. I'm 175/6' and the medium fits pretty much perfectly. The only thing is the shoulders are about half an inch narrow for me, but it's not too noticeable. Fabric is really good for the price, not as thick as more expensive overdyes, but still quite substantial. The navy is killer. I just placed my order for the khaki and olive.
Bothers me to the extent that I won't be buying any more. Still a great piece at a great price for those that fit into them properly.