Tim, I got your PM, but since y'all have the same question I'll just answer it here.
I'm 5'7" about 170 lbs., originally I ordered the jacket in a large, it was way big, but not big enough to wear over the pfd. I believe the pfd is meant to be worn over the jacket. I sent it back and got the med., for me the medium is a good fit, but with the pfd over the jacket I felt it was just too restrictive, just too much bulk.
Honestly, when the weather starts to turn here the water temp. drops also, so I tend to ride a lot less aggressively. So usually I just wear a sweat shirt under the PFD, I also have a pair of neoprene socks, but that's about it. This is not much of a sales pitch for selling the jacket, but I'm just trying to be honest.
Lou