We have air leveling only on our 2019 Red 340. Like is said above, the higher end DP's have both as I understand it. It does work really well, but like with hydraulic systems, if the site is sloped too much I have to drive one of the sides or front or rear tires up on my rubber pavers I bought from Home Depot to allow the air bags not to hit their limits when leveling. Like SargeW says, when the washer and dryer are going, everyone knows it. The coach shakes quite a bit (not awful, but annoying). The Red 340 is considered an entry level DP, so I just live with it. We often do the laundry at the facilities provided in places we stay anyway since it can be knocked out quicker.
Tommy & Franci - Houston (Clear Lake), TX
2019 Allegro Red 340 33AL
2020 Jeep GC Limited-Blue Ox Avail-M&G Braking
Part Timers-Looking Fwd to being Anytimers