The mock on this shirt is too big and too loose, it's about 2.5" wide, should be shorter for a true mock in my opinion. I ordered a large because of other reviewers notes about shrinkage, when I normally would wear a medium for this type of shirt. Before washing, the sleeves are already too short for me, so I will have to use a rack and air dry this. I'm 5'11, 165. I had a $10 coupon, so I can't complain too much, but I doubt I'll buy this again.
Just my two cents, but I like the shirt. Contrary to what many have posted, the fit is perfect for me. Fit will be relative to the individual. I am not a big guy, chest 42, 5'9", but a size large shrank to a perfect fit for me, sleeves, chest and body. Also, I prefer the loose fit of the neck--tight turtlenecks are too confining and too warm for me. The casual look as well as the soft feel and weight of the material is great for around the house or for under your jacket on a motorcycle ride, especially with the mock tee neck. All in all it serves several niches for me and I intend to buy more. Those who have been disappointed are either a different shape than me, or have different expectations.
I would suggest getting the Tall size if you are 5'10" like myself and have had Lg sizes on some brands shrink too much in the sleeves. It shrank after first washing/drying cycle of course but fits good now, with about 1/2" to spare for future shrinkage as all do. Fits nice at the neck-it's higher on the neck than a lot of other mocks I've had over the years-I like it. Will try solids at some point now that I have a feel for the mfr of these. Will have to wait and see what many washings do after time but I'm satisfied so far.