Ya, really depends.
A Monti. cap. can secure itself to rock without help in 24rs or less in ideal circumstances. Usually a week on the outside. On the other hand a lot of corals will never encrust or take hold on their own.
It also depends on the product.
In general I like super glues a LOT more than epoxies. Their downside is that they cure so fast in saltwater that they are pretty brittle, which limits strength. Probably not a factor in most scenarios but good to be aware of.
Epoxies are much much stronger when cured but in practice they really aren't very sticky. Good only in certain situations IMO.
-Matt