I purchased a R-Com 20 from a breeder who thoroughly recommends them after hatching over a 1000 Chocolate Orpingtons & Chocolate Bantams in hers, My advice would be to add the additional trays, they do a chicken one If I remember this makes it easier for the eggs to turn evenly, as I have only the standard tray and also have different sized eggs and they seem to move about in all directions.
I am currently incubating 6/8 mixed Cochin Bantam Eggs, 2 Silkies, and 10 Columbian Buff Cochins in mine with my first one due in a couple of days, I will report on how everything goes.
The incubator is spot on for Temperature and Humidity and if you go for the pro version it can be set to run automatically through the entire incubation process as it even stops the turning system when it is required.
I can only talk about this type being I have not used a good incubator before.
I hope this is interesting to you.
Regards
Dr Rob.