Porpoising is fascinating - last seen in the ground effect era. I saw an interview with a designer from Williams in the early 80's (sorry, can't find the video) who explained it's difficult to model the motions, because they're front to rear as well as up & down.
Maybe Adrian Newey is old enough to remember the problem from early in the Red Bull's design, and avoid the problem?
McLaren seem to be on top of it too.
Ferrari & particularly Mercedes will work through it, but how long will it take? If Merc are bringing parts to Miami you'd hope they'll take a step forwards.

Sauber appear to have built a cracking car - one of the few on the initial weight limit: their challenge I guess will be to keep up with developments.

All in all the new rules seem to work - cars can follow closely enough through corners to overtake without DRS. They're just so darned big & heavy :-(

Will

Formerly Aero S5 #80
Currently 911 (992) Targa in python green