The blue is a little difficult to get hold of. I was told at the Bond St boutique they sold their last 2 allocations were not expecting more this year. The silver was in stock when I looked. Wempe is also approved seller so if you looking for one -maybe ask around. New I think the blue will be difficult to get below list. I bought one second hand just still within the 2 year warranty but with all bits and cards - below list. They others could probably be negotiated at an AD from new.
It cleverly has a soft iron casing ring forming a faraday cage to protect from magnetic fields even though it has a display back
Screw down crown and case back and crystal with water resistant to 150m (some literature say it has been tested to 15bar)
I have read it is a more robust movement (than the ultra-thin Cal 1120) being larger and thicker - designed to take a knock or two - but like any mechanical watch I'd avoid dropping it on a concrete floor.
Martyn