|Can we get some more spikes on this guy?|
They broke the mold of 5th edition by being the only troops to exclusively have poisoned shooting attacks. That Greater Daemon of Nurgle? Wounds it on a 4+. They wreck monstrous creatures big time, and are really just the same as Bolters against any other troop. The only downside is that shooting against low toughness models, like Gretchin or normal Eldar, it's the same chance to wound a puny Grot as it is to wound a Carnifex.With a normal bolter you get to lay out low-toughness hordes like Hormagaunts, but with splinter rifles - you have a little more trouble. That's what balances them though, they can assassinate high-toughness models, but they have trouble with big hordes of low toughness models. And they're completely ineffective against vehicles, which limits your tactical options once your Raiders get popped(Oh and they will!).
They can footslog it with two Dark Lances, or get nice and snug in a Raider with a Blaster and Splinter Cannon, and sit back on your table edge and spit hate. The only thing they suck at is assaults, but if you manage to make it to pain token number two, WS4 S4 will start scaring people. Six initiative with Furious Charge ensures they go off before loads of other things, which makes getting hit back a much more lucrative prospect than you'd first think, having a look at your target to assault. Options for plasma grenades, or a Phantasm, you can actually assault with these guys. But, thinking of it as anything else than a desperate measure, and I'll start to wonder what's wrong with you. These guys have some of the best guns in the game.
Coming in at 9 points, they're a solid investment for a core of troops. Their models are superb, and you can really get some interesting poses from the little guys. The sets were made so that you could nab an arm off a Warrior, and put it on a Wych, or Reaver, and have them all be backwards compatible like that. A really smart move, and a great use for whatever little bits you'll have left over after you get done making them. Mostly just a sprue full of spikes after you make 10 of them.
I really love the little dudes, but the 5+ save on them is just plain hurtful - everything outside of lasguns and shootas are going to be stretching your ass open like you've never had it done before. You'll be pulling handfuls of these guys if you get hit by Bolters out in the open! Don't let them out of the protective womb of that Raider, otherwise Bad Things(tm) will start happening, and very quickly at that.
All in all, they compete very well for being picked as a troop. Against Wyches and Wracks, they offer something that neither of the two can dish out - sweet, sweet firepower. 10 in a Raider with a blaster give you a great tank hunting unit, letting you use the 18" range of the blaster for more immediate threats, and allowing you to target a seperate vehicle that might be camping with its 36" range. You won't be getting pain tokens by tank hunting though, so if you lose your Raider, say goodbye to the squad. They won't have any staying power at all.
A lot of people use 9 of them in a Raider with an Archon, to deliver him with a Webway Portal. The Warriors really add nothing to his combat capability, and also it puts your Warriors sometimes wayyy too close to the front lines, since an Archon is most comfortable in the thick of it. I think it makes more sense to stick him in a Venom with a few Incubi, personally. Or take Trueborn with blasters, for a little gank posse to bugger whatever is threatening your Archon.
They're a real multi-purpose unit, but they excel the most at shooting. Set them up in a Raider with Splinter Racks, and go to town.