Unlike with potions and pills, spells cast using these objects can or will affect characters other than their user (and, for staves, every character in their room); and, unlike scrolls, brandishes may (usually) be used multiple times before being fully consumed. For these reasons, many players may find brandishes to be rather handy during certain circumstances. Clerics, for example, may find them useful either for healing multiple groupmates simultaneously without using their expensive mass-healing spells or for continuing to heal their tank even after their mana has been depleted. And characters of other classes may find them useful for serving as supplemental or substitute healers in groups. Two important drawbacks of brandishes are that they may take time to collect and that they can be very heavy.
For a list of objects sorted by the type of spell they provide, see Suggested Spellcasting Gear