Hi. The Longines Spirit looks good in a number if ways. But what's with the absence of a screw down case back in favor of screws? This doesn't seem secure to me, especially when opened on a service and then closed again. Some screws being tighter than others would compromise the seal.
I don't know about this watch. It seems like a weak link in the chain.

 

Looks at G Shocks...
OMG no one ever told everyone that wears a G Shock that it is not waterproof....

 

Actually a better system in some ways. For example, the seal isn't getting dragged around, it's only subjected to compression.