Well, the 4th Gen PO is the best 42mm PO out right now. You will not find any that is better than that. The UPO is the BEST of the PO line because it matches it well.
There are still minor flaws to the 4th gen from the Gen, but they are quite small. If the hubby is a stickler for details, then he might prefer a Genuine. You can easily tell the rep if you are a WIS by looking at the AR and the pearl.
I guess in the end:
Do you know if the hubby really really wants a 42mm PO. If so, then might as well go GEN. If you dont know, then a rep is good to go for him trying out. If he likes it and wants to keep it, there you go? if he likes it but wants to upgrade, then it was a good trial investment? if he doesnt like it,then you saved yourself a lot of moolah not buying the gen
If his wrists are on the smaller side, he may feel the ultimate is too big.