Aside from the bed being of different materials, and perhaps some slight design changes, these seem to be almost the same.

I have used both and happen to think the PTB is slightly more rigid, though with a lesser build quality then the 45N.
I like the rubber coated locking knobs on the Shen hao better then the bare metal on the Chamonix, though i am sure over time, the metal only ones will last longer.

Is there anyone out there who used both cameras that can comment?