I'll do a quick writeup of mine as well I guess:
My army (Tau)
Commander Shas'el, Plasma/Missile/Shield
2 Crisis Suits Plasma/Missile (great for dealing with everything: up to 12 shots with good strength and AP, can take out marines, terminators, vehicles, and monstrous creatures with ease)
10 Fire Warriors
10 Fire Warriors (for controlling objectives and dealing with lightly armoured models, even AV10/11 vehicles)
Hammerhead w/ Railgun (large blast for bunched up models, or a dreaded S10 Ap1 shot for taking out vehicles of any make, or monstrous creatures).
In general, I'd like to point out that I feel that Tau got a step up in power with 6th. Fire Warriors being able rapid fire 15" is great (as it puts them at 9" away from an assaulting enemy rather than 6"), and moving 6" and still fire a single shot at 30" is a significantly bigger threat range than their previously only being able to move and shoot 12".
I've also always felt that Tau are comparatively more powerful in the <1500pt range. Being able to bring relatively resilient, high strength good AP firepower in a small number of units gives Tau a large amount of threats whilst other armies in the point range are struggling to bring sufficient counters. I find this switches around at ~1200-1500 pts as other armies start being able to bring most resilient units and comparable offensive power. So I don't find it overly surprising that I did well in the 600pt game, especially as I drew three matchups against armies with poor armour saves.
Kai's Dark Eldar: 20 Kabalite Warriors, Void Raven, Archon
I got first turn and set up with a relatively defensive position in some ruins. The Dark Eldar deployed very far away, mostly hidden by some LOS-blocking buildings.
I chased the DE around for a few turns, moving the FW into shooting positions whilst the DE ran away from the S6 Ap4 template of the Hammerhead. Eventually I got a point-blank shot and instant-deathed the Archon (unluckily failing both a Look Out Sir AND a 2+ invulnerable... bad luck Kai). The void raven killed a crisis suit when it came on but eventually it flew off the board, I killed the last kabalite warriors cowering away from my tank, and the game was over as Kai had nothing on the table. 20-0 victory for tabling my opponent.
Dion's Orks. 2 squads of Boyz in trukks, weirdboy, a squad of rocket boyz, and a squad of nobz? (something with guns that shoot D3 shots per turn)
Dion deployed his guys fairly bunched up in the open and took a few heavy rounds of shooting which wiped out most of his army. With railguns auto-penetrating a Trukk and exploding it on a 3+, and getting glances with my basic weaponry on 5's, they didn't last long to my shooting. One squad of boyz got into combat and demolished a fire warrior squad, but were gunned down by the remaining fire warriors and the crisis suits before they could close. 20-0 victory for tabling my opponent.
Marks' Tyranids. 5 Genestealers with a broodlord, a Hive Tyrant, and a trygon prime. 8 models total.
I deployed on a hill with view over the whole board. The #3 and #4 objectives were both in my zone. Mark deployed in as much cover as possible. This definitely saved his army as it took nearly 2 turns of shooting to kill the genestealer squad. I was having appalling luck with my shooting from the Hammerhead/crisis suits and didn't manage to put any wounds on the Tyrant. The trygon popped up and again proved resilient to shooting, before it demolished a squad of firewarriors. The other firewarrior squad kept dancing away from the Tyrant, failing to put any wounds on it but staying out of Mark's abysmal rolling for change distances.
Eventually the Trygon was in position and I had to choose whether my firewarriors were eaten by the tyrant or the crisis suits were eaten by the trygon. I decided to sacrifice the warriors, bringing down the Trygon in a round of shooting, and the warriors predictably became dead. When Justin called out 'One minute remaining!', Mark was winning with a denial model in my deployment zone. I furiously rolled the dice and took a wound off it with my hammerhead: and finally, the crisis squad got a good set of attacks and scored 4 plasma wounds denying armour saves. Victory, snatched from the jaws of defeat! End result was 20-0 for tabling my opponent, but it could very easily have been a defeat.