I am about the same weight and height (152 lbs and 5'8"). I have the Navy polo in medium and I found it has to much room in the waist. I also find the sleeve openings too wide. Otherwise, the polo is great, especially the fabric and the collar.
Oh right. I was viewing the Sales section under 'View All' and the items I looked at are all on Clearance. Anyway, I dropped by one of the stores over the weekend and bought couple of shirts. When I got home, I found out that one of the shirts still has the security tag on... Funny the alarm didn't go off when I left the store.