I'm 178cm and have ordered the large. It's personal preference but I would have a look at the geometry and compare it to bikes you have ridden to get an idea, or get a sit on one if you can. The seatpost is nice and short on the geo charts.
Interesting to read the opinions, I've got a One77 incoming and a bit nervous due to lack of reviews and information. I did think the BB looked a bit low. Hopefully will get on ok with it.