Acctually, I've had trouble with both grolsh bottles and E-Z-cap bottles from the lhbs. Never had an infected or oxidized mead, but about 5% of my beer in such bottles ends up flat. And believe it or not, the original grolsh gaskets seem to make a better seal than the replacement E-Z cap ones, though I have had trouble with both. I don't know what the problem is because no one else has reported any trouble. They guys at the store use them almost exclusively.
Never had any trouble with bottle bombs in grolsh bottles. I forgot one in the freezer once and rather than break, the ice simply blew the gasket out of the way.