I can only imagine that the GOTCHAS in using vertical speed in a climb is that if you select a vertical speed beyond the energy capabilities/ceiling capabilities/ that you might stall.
I seem to recall a Mexicana DC10 that stalled due to inattention in this mode...is that what you meant?
of course selecting mach hold/IAS hold can result in a climb that is protected against a stall, but the nose can ''hunt'' if there are airspeed vagueries.