18" wheels are now available as an option on all trim levels, I think this provides a smoother ride and better range, but it can adversely affect other factors including cornering / stability and stopping distance so it depends what your preference is (plus how good the suspension is in the vehicle). For example: https://www.autocar.co.uk/car-news/features/are-bigger-wheels-really-ruining-ride-quality and https://www.jdpower.com/cars/shopping-guides/what-difference-does-the-wheel-size-make
When on a test drive last week of an RZ 450e Premium Plus (4WD), we found the ride to be good, better than my 2016 NX 300h (18" wheels) 4WD and almost as smooth as our 2021 UX 300e (17" wheels) Front wheel drive. Handling most manhole covers, speed bumps and potholes well. My SO and I took it in turns to sit in the back to look after our baby and both had the same opinion of the ride quality.