I can't compare, not having tried a Night Vision jacket, but I'd say that the Large fits me fine but is a little tight under the arms with the long sleeves on. I suspect that this is where the 'come up small' comments come from - the sleeve zip at the front takes away the 'give' from the fabric and makes them feel a bit tight. With the long sleeves off, it's a great fit.
Once I'm riding I don't notice the tightness, maybe when in position the problem goes away?
Try before you buy, I'd say - hope this helps!
3 years, 11 months ago