IR late model dry suit. advice

I found a GREAT deal online for an Immesion Research Dry Suit. It’s a medium size. It’s the older 3 layer suit which is now discontinued. Do these suits run tipically bigger or smaller than average? I believe it will fit me, but wanted to make sure. If anybody has any experience with these suits and could share their opinions, please I would love to hear about it before I pull the trigger and order it. By the way, the IR site has the new suit in medium size suitable for somebody up to 32 waist and 16 neck size. (I am about 5’9" tall) That’s about my exact size with not much room for expanding. If the old suit is about the same, I may be about a right fit. Opinions welcome.

Probably too tight
I’m about the same size as you and IR’s medium is too tight for me.

Across the shoulders and under my arms was constricted and binding.

err on the big size
In general, a little extra fabric on a drysuit isn’t a problem, whereas a drysuit that’s just a little tight is a real pain. If at all in doubt I’d order up a size.

difficult to say
I would contact IR, they are quite good with customer service.

I have IR DD, Medium. I stand 5.9, fits me quite well, even with a whole bunch of underlayers.

I’d assume that the cut of drysuit hasn’t changed much, but it is better to err on the side of caution and contact customer support.