Well, I am a total rookie when it comes to hatching eggs. But I will say that I am using the diffuser/perlite with all of my clutches and EVERYTHING is doing perfect on it. Nothing moldy, nothing dried out, and so far one whole clutch of eggs hatched. I removed the diffuser and cut at day 52, so there was no issue with them getting hurt on the diffuser.
The coke-bator is going great and I have a few thermometers and even a remote thermometer display next to my computer in the office so I can keep tabs on temps without getting up.