42mm PO .. advice

[Q5?]

Q5

What did the 4th Generation have to make it so good (apologies for the 'noob' question lol)

And what are the tell tale signs that you have a 5th Generation PO.

I am in the process of obtaining a 42mm PO described as 'Ult'. Should this be a 5th Gen?

The 4th Gen PO had a better pearl and HEV.
The 5GPO has a bigger HEV and the pearl is too large but has a better dial, SN# and globe on the case back.