Zadok_Allen: The low level opponents... that kind of stuff is still boring, if less so. Nothing could ever shine there.
Yes, but keep in mind that low level opponents can still do large amounts of physical damage.
Elementals are especially notable there; they can be summoned by higher level enemies, have a lot of hit points, and hit really hard, but their level and most of their resistances are low, making instant kills (both weapon and magic) particularly useful here.
Also, when it comes to multi-target instant death spells here, using them against groups of low level high HP enemies (like lesser Rapax) will greatly reduce the time you have to spend fighting them. That's why I really like the Quicksand spell.
(Against low level low HP enemies, the way to end the battle quickly is to spam multi-target attack spells.)