I totally agree. Magic in Howard's setting is terrifying and wierd - nothing like the "sciency" approach of D&D. In a way the magic described by Howard, Lovecraft and, to a lesser extent, Tolkien, is almost the last pure or uncorrupted (note: definitely not uncorrupting) attempt before everything got flooded with D&D-style spell-vendors. Not to mention 11 year olds casually and predicatably breaking the laws of thermodynamics with a polished stick.
The sorcerers Conan meets are almost all supremely evil and powerful in their own right, and yet described in a subtle way. And without the knowledge of what spellcasters can do in D&D, their arsenal is awe-inspiring. Most of them live for centuries, in itself a pretty neat trick, and have spells often way more practical than Fireball.
Think of Xaltotun who can summon a super-fast, hovering chariot. Very practical. Or Khemsa who can hypnotize someone so profoundly that they kill themselves. And both of these dudes can best Conan in single combat with their bare hands!
Yes, there are also guys tossing incendary clouds down a hill but they aren't that prominant.
Now, of course there are practical spells in D&D, but my problem with them is that they are reliable, predictable and consequence-free.
