I am guessing a manufacturing problem and a bad batch. If these ESCs are blowing this easily it must be that because they certainly wouldn't have missed such an obvious problem in testing.
Unfortunately, returning ESCs is likely going to lead to the same problem since they likely don't have a new batch. They probably had a bunch of truck shipped and a stack of spare ESCs which are from the same batch that they are giving people in the meantime knowing they are the same and likely to blow.
I think high C-rated batteries may help. For the people whose trucks didn't blow up, what was the C-rating? I ask because the charge and discharge cycling of the caps in the ESC will get hot and blow if the batteries can't supply what the ESC needs (ie. they don't like to work out of phase) so its not hard to believe if the motor is pushing the ESC to its limit that the batteries could be heating the caps too much if they aren't a high c-rating.
Should I just get it over with and blow my ESC when I get it and go on to the MMAx pro?
On an unrelated note I am in India right now and have been using my crawler in some amazing arrangements. If I didn't have a wonderful family I would throw away my return ticket (and have my XS and other RCs mailed here).