I considered taking a battle standard bearer with a standard of shielding in preference totwo ranks of Dragon Princes, but I feel he's a little brittle. Swordsmasters can rout any unit they outnumber that they can beat, and they're immune to fear. I like taking monsters without riders because they can't be challenged. Griffons cause terror and have high Ld. They're great for taking out lone wizards, war machines, or charging in from the flank to support the attack on a unit.
Terror is great against certain opponents.
I often use them as a screen for cavalry or the Swordsmasters. I use the High Elf Archers as a normal missile unit or sometimes as a screen for the Bolt Throwers as well as a missile unit. This depends on terrain. At a pinch I'll set up the archers in two units of six, so as to provide a better screen. I'd like to have taken some chariots, but I'm so bad at using them that I'm just not willing to muck them up again.