How is the sizing on henleys? I look at measurements on ebay and they are all over the board...I can't tell how much of this is seasonal/model variation and how much of it is that different sellers are just wildly different at measuring (especially since it is not a rigid material). for reference, I'm wearing a Medium lands end tailored fit polo right now since they are pretty close to what I want. Dress shirts are usually something like a BB 15.5 slim or 16 extra slim or a 16 RL custom fit. I would think I should go M for the henley (I have recently been preferring M t-shirts to my vast stack of L t-shirts) but some of the measurments make me think L is right.