None have bounced... That I know of
But yet, as from my original post, I've primarily used Paypal for all my ebay/hobby collecting activities. Yes, I've received several checks in the mail, and I don't remember any that have been lost in the mail nor have any bounced to my knowledge. Another consideration is that with this hobby being so specific, your talking about only 5,000 active chipper (maybe)? So because it's just for this, and not some desperate person trying to buy groceries floating the check for a couple days - the check is most likely not to bounce.
good point, but it still a possibility.