I'm 175cm, 77kg and bought the size M, which fits me very nicely.
The leather is softer than I expected, and it's pretty easy to move around in, for a leather jacket. The armor could be better quality, an upgrade to D3O would be welcome, but at least the whole kit is included in the price, which is not always the case, some manufacturers like to forget about the back protector. I'm also wearing it off the bike, without armor, and I blend in completely, the normies don't even suspect that it's a biker jacket. (This is a slim cut, quite snug around the waist, so if you're sporting a beer belly at the moment, maybe Icon or some other American brand is a better choice.)