Oh, I do candle! And I candle several times during incubation, too. If I have a huge bator-full, I may do a few one day, then a few days later, do some different ones so the bator isn't open too long. I probably candle four times during an incubation. If I'm just checking fertility and dont plan to incubate the eggs to the end, I may candle starting at three days and every day till about day six before I decide to crack them open or allow them to continue on.
The drawback is just what you said and it's a biggie! An seeping or exploding egg can ruin the entire hatch.