I've used the RCBS type twice (same as the homemade type) and both times it just tore the head off the case:
Two things I failed to do that might well have saved the day:
One is submerge the die in Kroil or other penetrating oil for a week.
Two is to drill and tap the case, then freeze the die overnight before applying the tool. Brass has a larger linear coefficient of expansion than steel, so it shrinks more during freezing.
Never tried the Forster type, so I don't know how it compares?