Are you saying that you fill the bottom of the hova-bater with vermiculite and sit the eggs down in them without using egg boxes at all? Just want to be clear.
I've heard mixed reviews about hova-bators. Some good, some not. I'm not sure what they were using as a thermostat. I personally, have placed an order for a herpstat for my rack and quarantine room and I'll probably buy another specifically for my incubators.
I'm also not opposed to having several incubators. Ideally, I'd love one per clutch, but I know that's not always realistic. So if I can get two in one incubator that would be awesome. I know with corn clutches, you can get 20-30 eggs easy so each hova-bator can hold one or two clutches max. Not to mention, because of temp differences, I'd need two anyway.