I brought my Nids to 'Ard Boyz this year and though I had to borrow from two different people, I still don't think my list was as tight as I would have liked it. Here's what I took:
3x Spore Mines
3x Spore Mines
Looking back I think I'd rather have another Tervigon and two more Trygons instead of the T-Fex. However, the Gargoyles+Venomthropes is a golden combo. If you string them out right, you can still get the cover save while still moving full distance. The formation looks something like a T.
Anyway, my first game was up against the other Nid player in the store, from whom I borrowed the Venomthropes. He has an all-drop list. He managed to drop a pod of warriors in behind my lines and nearly killed my traitor, but only because he whiffed his rolls pretty bad. I didn't kill his traitor either and got a minor victory. Had he killed mine I would have taken a minor loss.
The second game was up against Orks. Ed from LATCS was running a Battlewagon army. For some reason he put everything except his Lootas in reserve. That sole fact allowed me to win the game. I advanced with everything and on his turn two realized there's no point in going after his objective as it was only worth one point as opposed to the other quarters which were worth two. Ed's army came in piecemeal but even then I couldn't stop all his battlewagons. I don't think I killed a single one. However, I did slow him down. His Lootas were also on fire, rolling a 3 on their D3 every time and hitting well over 50% of the time each time they shot. They took out my Hive Guard, put 5 wounds on a T-Fex and killed a Tervigon. We only got to turn 4 (two horde armies will do that to you) and I held my objective plus the center one while contesting his. If he had started on the board there's no way I could have stopped him in time. That netted me a massacre, however if the game had gone on I'm sure I would have lost.
The third game was against Chaos. The game was pretty rough and tumble and I had a hard time killing his vehicles. I may have killed one. I immobilized his Land Raider with a lucky hit from a Broodlord but couldn't finish it off. He killed a lot of my stuff and I got a minor loss.
In the end I took third. I ordered a Ruins of Osgiliath terrain piece as it's a cool piece and could be used in Fantasy or 40k, plus Mordheim.
I learned that I'd rather have the extra Trygons and another Tervigon as my HQ. I also learned that I'm going to need at least two more boxes of Termagants, not to mention at least two boxes more if I get the third Tervigon.