Ordered this in a 17.5, since that IS the measurement of my husband's neck - however the shirt was gigantic! Have to pay gigantic shipping chanrges now to get the correct sizing - which I will have to guess at - because obviously you can't go by the 'measurement charts' on this web site!!
Shirt fits well and is very comfortable. Seems to wear well also. One minor problem -- the collar button hole is horizontal to the ground instead of vertical like the shirt front button holes and every other shirt I have ever owned. It makes it very difficult to button the collar. If it worn without a tie, it would be perfect.
I travel all the time (typically out on M, home on Thurs. eve) for work, and I need a shirt that doesn't need a ton of TLC but which holds up really well on the road. I couldn't ask for a better shirt, and when these go on sale (solid, tattersall, stripe, I love 'em all) I load up, if I have the budget. But they last so long that I really don't need to. They hold a crease unbelievably well and look great. The slightly heavier fabric pairs well with jeans or chinos, so it's a shirt that bridges the workday and "off-duty" time really well, too.
The fit is very true to size and the material is relatively substantial. The shirt stands out from others in my closet in that it truly comes out of the dryer without wrinkles whereas all of the other "wrinkle resistant" shirts still need much ironing.