Like I said, I don't have specific details of the other policies' limitations, but I highly doubt there's no limit to "accidental" coverage. SquareTrade limits your coverage to the maximum value of the device, so even though they don't limit the number of occurrences expressly, they will only repair/replace to a maximum value of $499 for a $499 device.
I'm pretty sure Worth has similar limits.
And more than 2 incidences of accidental breakage in 2 years is a lot. If you have kids who are prone to mishandling $500 devices then it's hard to call it an "accident" if you keep letting them use it unsupervised after 2 "accidents".
I just talked to Worth to go over my policy and there IS NOT a set number of accidental replacements. They only thing is that you can't have numerous replacements in a very short time. (ie Your iPad is stolen 4 times in 1 month.) So while it may be 50 a year, I have relief knowing I can drop it and have it replaced as many times as I want. I'd hate to accidentally drop my iPad with AC+ once and know that I have only one more accident during my 2 years. I'm not a very clumsy person, but crap happens.