My understanding is that a couple of years ago Cube changed their sizing to be more in line with other manufacturers. Certainly I used to be a 60 in Cube compared to a 58 elsewhere.
I would certainly be slinging a leg over one at my LBS and giving them at least the chance to get close or match the internet retailer.
Yes, that's my understanding.
My Cube bike is a 56cm and I'm only 5'7" !!
When I looked earlier this year at changing, their latest models are now more aligned to "normal" measurements. In their new sizing I'm more a 52/54.