Only game I've played with the new book, I ran 2x 10 warriors in raiders, with splinter cannon, splinter racks and dark lance on the raider as upgrades. In all honesty I see this being the core of any army I'll build for the immediate future as it's an excellent unit. However, I think that the strength of the Dark Eldar lies elsewhere in the codex, and we have so many options.
For a Realspace Raiders detachment I'd only take the two squads, possibly a third small unit if I find myself with the points, as our fast attack choices are too good. I'd take the above, an HQ with escort, all the fast attack I wanted, some anti-armour, and then come back and revisit troops last. In a combined arms detachment, the only benefit to taking it over Realspace Raiders is objective secured on troops so I'd definitely want a third troops choice minimum, and wouldn't be truly happy without a 4th. Most likely to be the above warrior/raider combo, 10 wyches in a raider, and 5 warriors in a venom.