I installed a pair of the Moog BJs with the minimal/hidden boot about 6 years ago. Still seem to be holding up fine, no noticeable grease loss or signs of BJ wear, though if there were a tiny tear at the bottom of the boot, I wouldn't be able to see it...
I did have some come out the top of the boot the last time I lubed them, just means they were full and makes me think there wouldn't be any cracks elsewhere or else the grease would have leaked out there (path of least resistance) rather than the recessed boot valve area at the top.