I think it was about 4 or 5 hours. (I started it before heading to work) But I then cleaned it off and put it under UV light for a couple hours to make sure it was fully cured.
I'm not sure about the other ones, but mine has a charcoal filter on the exhaust. Doesn't stop the smell 100%, but it's definitely barrable even with a stinky generic resin.
Especially when you consider that the printer is $199
https://www.amazon.com/Creality-Photocuring-Filtering-Off-line-Printing/dp/B082XDH8NB/ref=mp_s_a_1_4?dchild=1&keywords=Creality+resin&qid=1611626239&sr=8-4