OK, I have done the hard boot sizing long time ago. Surprisingly for me at the time, my true size was around Mondo 27.5. At the time, my current hard boots were Mondo 29! Now I am in Deeluxe 700, shell size 27 and liner 27.5.
Now, when I tried to size myself for soft boots, I thought the same rules apply as well. For a foot size 27.6 cm, I bought (thinking it might be even big) Burton boots size Mondo 28 or US 10. They are tight! Really! I couldn't ride for more than a couple of hours at the time. I got the next size 28.5/US 10.5 and they feel awesome. On the other hand, here is what Burton themselves recommend - http://www.ridealer.com/Burton-Driver-X-2014-3.html. According to the chart, you have to go to the bigger size.
I just want to see what other people have experienced. Obviously, one goes with what feels best........ at the time :).
Thanks!