My machine WW90T534W - Series 5 :
eco-bubble - yes
Add Wash Door - No , but on most washes if the water level is below drum and water not hot and not spinning I can pause the machine and the door will open so I can add more items.
Smart control through App. - Yes , and I like this, also being connected to app you can check diagnostics on the machine and make sure all the components like motor/heater/door lock is working as it should
Vibration Reduction Technology- well if its got vibration reduction technology I would hate to hear it without because mine vibrates a lot. especially when drain pump is going, almost like drain pump is vibrating off something inside the machine , and when spinning there is quite a bit of vibration/tapping noise too!
Quick Drive- no, my particular model does not have this - just a normal drum in it.
Digital Inverter Motor - yes my machine has this , I like these motors. Huge improvement on the old carbon brush type washing machine motors.
Ceramic Heater - hmmm.. Interesting , I don't know if mine has ceramic or normal heater element at the bottom of the drum ... and I am not going to take it all apart to have a look.
