I have a Whirlpool stacked set: washer and dryer, and LOVE them.
Yes you can soak in them. It has a soak cycle.
It's so easy to see into the dryer when it is stacked above the washer. Takes less room, too.
Yes you can add clothes you have forgotten. The little green light stays on for a few minutes. After that is off, you can't add anymore, but you can for a while.
I can do a very large load. The directions say you can add as much as you like as long as you can get the door shut!
I use Melaleuca detergent. Very concentrated, so you use only one half ounce. Works very well.
Melaleuca also has a gentle bleach which works wonders. I put my whites on "Whitest Whites" and can't believe how white they get.
I never close the door completely when not in use. It doesn't have to be wide open, but just don't let it latch. I've had this machine for more than 3 years and never put any Afresh in it as called for and never had any mold or mildew.
I do the same with the dryer door. It shouldn't be latched. Just leave it almost closed, and it stays smelling fresh.
I use no dryer sheets. If there is a little static electricity, it will dissipate in a little while.
I hope this is a thumbs up for front loaders. Three of my daughters have them and love them. The other daughter has a top loader with no agitator, and hates it. She says her clothes do not get clean.
Hope you enjoy your new washer, whatever kind you get.