I hafta agree. If your OEM boots split, it's not likely that a glued together boot will last more than a few days.
BTW, MechaTech & Dorman boots didn't last for me either. They guy at the axle shop put on some boots imported from Canada that finally did the trick (look just like OEM). Unfortunately, I was never able to find them retail.
Someone posted a long time ago that Advance Auto over the counter boots are incredibly beefy & hold up well (also look like OEM). They are a lot cheaper than MechaTech.