Hello, I don't remember much of the gist of this and this is my first report. This was a simple 2v2 with annihilation. 800 points friendly match.

Group 1:
Flyrant w/ VC ST Warp field
12 'stealers with TS and EC
16 spineguants
16 hormagaunts
3 warriors with devourers ST and EC

Stealth team,
2x6 firewarrios
3 crisis battle suits

Group 2:
10 tactical squad with a plasma gun
5 scouts with sniper rifles and others
5 terminators with stormbolters and powerfists
1 dreadnaught with two flammers and a CC
1 captain/chaplin with the tactical marine squad

devilfish with firewarriors in it
1-2 crisis battle suits, can't remember
Stealth team

Group 1 gets to go first:
we develop all along the board, with tau on one side and nids on the other, tau plan to shoot, nids to rush as fast as they can.
Group 2 sets the SM across from the nids, and the tau across from the tau
The SM scouts infiltrate into a building and hide there, the Stealth team infiltrates in front of the building. Group 1's stealth team infiltrates on the other side of a hill near the other tau

Turn 1:
Group 1:
nids advance, However the tau placed the stealth suits way to close, my flyrant flys over and assults. rolled 3 ones! still killed two and the suits hit no one. However my spinegaunts roll one for running and my horde shifts slightly closer
Tau get little luck, jump on a hill, wound an enemy battle suit, and hide. Little else happens

Group 2:
SM sit where they are and shoot. Plasma guns, sniper rifles, and roket launchers and all shoot into the nid horde. At the end only 7 or so spineguants and 6 hormagaunts die to the volly of shots.
Tau move the battle suit away from the stealth team, advanced the devilfish, and shoot the hormagaunts, killing 4 of them. Suits and tyrant battle it out some more, 2-3 more suits down, no wounds on the tyrant.

Turn 2:
Group 1:
the nids advance further up, getting closer. Spineguants roll another one for running! the whole horde is spilling around the guants by now, with the rest rolling 4's, 5's, and one or two 6's. The hormaguants charge at the battlesuit, with 20-30 attacks the suit has no chance for survival. The tyrant rolls another two 1's but the suits run and the tyrand kils the other two.
The tau aim for the devilfish, but simply cant touch it. With most of Group 2's tau dead or leaving they simply couldn't do much. Also bad rolls really hurt their chance to hit some vehicles.

Group 2:
The marines stay about where the are, the dreadnaught moves closer and they begin shooting. the variety of blasts shoot into the horde doing very little, the shots scattering wildly with 5's and 6's. But the spineguants are left standing with 5 units, their doing their job. The scouts take a few shots at the tyrant and make a wound on him, 3 more to go.
The Tau try to tank shock the hormagaunts with a devilfish, the hammerhead shoots at the guants, all in all most of the tau are dead by now and the fire warriors haven't left the devilfish.

Turn 3:
Group 1:
The nids get within assult range with all their units. The ten stron stealers and one last warrior get into comabt with the termi's, and the hormagaunts and tyrant get in range of the tactical squad. The stealers get 10 or so normal wounds and only 3 rending wounds. The termi's save every rending wound but loss 4 to the normal wounds. We had a large laugh at that. The tyrant still rolls 1's but kills 3 marines, the hormaguants kill a marine. The marines strike back, but they simply miss every attack. At the end they took out 4 terminators and 3-4 marines with no losses. Poor rolls for the SM good ones for the nids.
The tau hammerhead finally hits on the dreadnaught, taking out the CC weapon.

By then we had to leave and with the nids only losing one full unit and the tau lossing 3, the Great Devourerer and the Greater Good take the win.

Sorry if this is incoherant and confusing, the whole group is still learning the fine points on the game, like how deadly the 'stealers can be, even against the termi's. Group 1's fire warriors should have deployed nearer to the nids, but he was expecting to have Group 2 focus on his units, not rush toward the nids. The Hammerhead does look ferousious with strength 10 AP 1, but its BS simply kills it. even with a BS 4, it doesn't hit that often. The massed number of die that the stealth team gives it better then the railguns single shot. However Group 2's hammerhead worked out well with sub-munition right into the nids.
The nids played well for their first time, the spinegaunts did what they were supposed to do, the tyrant was in CC turn 1 and every turn there out. The 1's in running did hurt alot though, as the main part of the army had to stay out for an extra turn because the guants were in the way.
The SM played what they should against a swarmy nids but the bad rolls simply hurt them to much. More then one blast template scattered off the board.
Group 2's tau placed the Stealth team way to close to the tyrant and so they were gone turn one. Also losing the battle suit early really hurt and so he wasn't able to do much for his team.
Group 1's tau placed the Stealth team well and they did what they should, till the enemy ran away towards the nids. The Hammerhead got bad rolls and they never took down the devilfish.

I've probably got some of it out of order, but I hope you can hear the gist of what happend durring the fight. I personally am surprised at how well the nids do in battle and hope to see them shine some more.