Raiders are extremely lightweight and extremely maneuverable. They come with a BS4 and armour of F10 S10 R10. They are a fast, Open-topped, Skimmer that comes standard with a Dark Lance (exchangeable with a Disintegrator for free) and with Night Vision.
They, much like the rest of the dark eldar army now, a unit of extremes. They are highly flexible in their role, but also rather expensive in terms of what they are. You can take any of the following options; Shock Prow, Torment Grenade Launchers, Enhanced Aethersails, Retrofire Jets, Chain Snares, Grisly Trophies, Envenomed Blades, Splinter Racks, Night Shields, and a Flickerfield.
Shock Prow. Allows you to tank shock and ram. Add D3 to your armour value on a tank shock
Torment Grenade Launchers. Reduce enemy leaderships by -1 within 6" and units must pass leadership to assault.
Enhanced Aethersails. Can move an additional 2d6" but cannot disembark or shoot.
Retrofire Jets. Vehicle can Deepstrike, however units cannot disembark
Chain Snares. All non-vehicle enemy units it passes over in the movement phase take d3+1 S4 AP- hits.
Grisly Trophies All friendly units within 6" can re-roll failed morale checks
Envenomed Blades. If assaulted every roll of a 1 results in a S4 AP- hit
Splinter Racks. All passengers may re-roll their failed to hit rolls with splinter rifles and pistols
Night Shields. Reduce ranges of weapons by 6" that are firing at the vehicle
Flickerfield. Gives the vehicle a 5+ invulnerable save.
So what do you do? You customize your raiders to fit your army. You take one, possibly two upgrades only, or simply go with none. If you think a flickerfield or nightshield is going to save you, it's not. So be prepared to lose all those points if you make these raiders expensive.
I haven't tried all the options, but here are the ones I've been looking at or fielded.
Raiders with Shock Prow say that if I lose my weapon, I become one. I like to keep it simple at stop here, but you could also add enhanced aethersails or torment grenade launchers with this. For me, I'll stay simple and just go with the shock prow.
Raiders with Grisly Trophies. Fielding backfield warriors with two darklances or splinter cannons, nothing says "Stay" than with a raider within 6" and getting a re-roll on your leadership. You might not be around long but at least early game a few of these raiders sitting in the backfield will keep you around a little bit longer.
Flickerfields. These are more expensive, and I've used them a lot. One day I know I will make a flickerfield save successfully. Thus far not one raider has lived because of a flickerfield. I will let you keep using these as I am done trying.
Nightshields. Also expensive and in my opinion a waste of points for a raider. Save your nightsheilds for your heavy support skimmers.
Disintegrators. There is a lot of hate on these floating around. I don't believe this weapon was nerfed. Small templates only ever hit 1 model in a unit anyhow (unless coming out of a broken transport or playing noobs), so I like the new longer range Heavy 3 S5 AP2 36" weapon. Sustained fire with the old ones as much shorter. Even though I like this option, it will be situational where I take it. In Raider heavy lists, taking two raiders with Disintegrators seems appropriate. Or if your list is very heavy with blasters and lances already this would be an ideal weapon.
There are other options as well, however these are the ones I am using. Splinter Racks I've seen used, but I don't like the idea of a 6" moving raider.
Think of your raider as a fast transport for your assault troops that comes with a weapon, not the other way around. They are open-topped so they are an excellent vehicle to disembark from (from any point of the hull). They can rotate for an extra couple inches of distance (do this first before moving forward), and can move 12" and deploy. This very quickly places your transported unit almost 18"(its not quite 18, more like 17 1/2) forward on a good move. So if you need that webway as close to the enemy as possible, you can really get it into a forward position.
Summary; before I start getting into the intricacies of using your raider. Don't load them up with too many options. Keep the price of them down. A Raider cannot do it all. Know what role your raider will be taking, and choose your options accordingly. If fielding multiple raiders, think of mixing it up. Simply spamming your options on your raiders is OK to start with, but you can really set yourself up with raiders performing slightly different roles on the tabletop. Example.. Raiders sitting in the back with grisly trophies, and raiders deploying assault troops with tormentor grenade launchers.
