I may be repeating some of what Archonbjorn said here, but what the hey.
Dark Eldar are faster even thatn the eldar and deal far more damage, to balance this they are weaker by far, unable to take wery mcuh punishment from shooting, unlike the eldar elites Dark Eldar elites actually have weaker armour than their stadard troops.
You will notice for the same points as a guardian you get a Drak Eldar warrior, aspect warrior stats, guardian price.... not a bad deal at all.
Dark Eldar are a treat to play when you get their tactics flowing nicely, they are a joy to watch as they surge across the field and decimate your enemies, mostly in one or 2 turns of arriving in close comabt range.
Eqwually i you go for a more shooty style of Dark Eldar army the torrent of Dark Lance and Disintegrator shots that can be poured out is truly astounding, as is the number of splinter shots from Cannons. Dark Eldar warrior squads get the added benefit of being allowed 2 Heavy AND 2 Special weapons in each squad allowing the formidable 2xSplinter Cannon, 2x Blaster combination.
All in all very different from the more resilient Craft World cousins. Also as you'll learn as a DE player when you see an 'elite army set up across from you (or cheesy some may say) such as 3 wraithlords, thats the time to start smiling.... Wraithlords, Daemons, anything of that nature is easily dealt with by a Dark Eldar froce and costs your opponent alot in points. Especially wraithlords.
