Hi there!
Despite their similar design, the Moon ReSea S for 2020 and the Moon Nuova City are certainly not 'almost identical.' The Nuova is heavier, more robust, and less compact. Although the seat is acceptable, I find it less practical (smaller in size). Both strollers are OK. If you prefer more robust strollers and you won't need to load the stroller into the boot of the car too often, I would say the Nuova can be a good choice. On the other hand, the ReSea is more modern, more compact (even featuring a foldable seat), more lightweight, and certainly more practical for frequent car rides, and overall, for URBAN use.
I would also like to mention a kind of middle ground - the newer stroller Moon Style. The Style is bigger than the ReSea and features larger wheels, while its weight is very manageable, which is pleasant. I prefer the Style from all Moon stroller systems - because it compromises with combining the best features Moon stroller systems are currently offering.