Currently actually debating just that. Haven't found many magic trinkets to carry around so far, so could spare the slot. To be fair though, the main temptation probably comes from the fact that last game, a well-aimed arrow killed the opponent's wizard (turn 1, I might add). And ever since, I have been wishing it was my wizard who had let loose that bowstring! Also don't have any direct damage spells on that guy, so it could be a reasonable way to get some kills in - although the spell selection is such that there tends to be something fun to cast anyway (love me those wild Imps). At any rate, I definitelly wouldn't go for a crossbow, costs too many actions to use more than once.
Still, upgraded shoot stat and potentially something like Glow on the target could get some decent work done.