@Max:

Seems like both would work - L fitting more like the 13, M more like the 08. I would check wether there's any crititcal measurement that you can't allow not to fit - for me it's always the shoulders. I size up if the shoulders are too small, even when the rest fits.

Thanks man, shoulders in the 08 have relaxed a bit and im liking the fit a lot more, leaning toward the medium. Birthday is coming up, lets see how much the wife loves me

tough time deciding what size to go with, can anyone offer an opinion?

my ihsh-08 sbg is a large western and fits snug, but i like the fit and dont think i'd size up. I just bought the ihsh-13 in large work/western as well, its a much more comfortable fit. Torn between a M and an L,  here is the comparison (sorry for the tough to read table and/or TL:DR):

|           13 L 08 L 91 L 91 M
P2P       22.2 22" 23 22.2
Shoulders 18.2 17.3" 18.3 17.3
Length    30.2 30" 30 29.2
Arm       26 26.5" 26.6 25.7
Waist     21.4   21.7 21
Opening  22.7     22 21.3
Collar     17.5     17.4 17 |

Thanks guys! Pretty sure I pulled off a triple on casual Friday. Does chambray count?

First fit pix. Great shirt!