Best Of
Re: Difference between models
Hi
All PI92-XXXX models are having a a new low-power mode that gives a much lower noise level compared with the old PI91 model. Thereby it's quite true that the i9.2 is more silent than it's predecessor.
Regarding the difference of the i9.2 models I've tried to sum it up below (comparing with the old i9). There's also other minor differencies but these are the essentials:
PI92-4STN (simplest model):
- Uses the same charging and batteries as the old i9
PI92-4ANM (middle model):
- Uses fast charging for quicker pitstop delays
- Has improved filtration
- Has improved cleaning performance
PI92-6DGM (top model):
- Uses the same charging as the PI92-4ANM
- Have increase battery capacity
- Has improved filtration
- Improved cleaning performance
Please note though that the models could be named differently depending upon where you are in the world but since those where the names you used in your question I tried to correspond them to marks previous post
I hope this makes it easier for you!

Re: Reverse order of cleaning
You can. Set up the zones. Do a zone cleaning. It cleans the zones in the list order. You can drag the zones in the list up and down.