Hmm, I can share a couple of interesting lessons from my smokin' boots-threatening performance:
1. It seems like Chaos Spawn would be good versus the White Scars biker grav-span army... they have no armour, right? Unfortunately, Spawn don't really do much in that scenario. Spawn are good at tarpitting units and slowly grinding them down, but the entire White Scars army has hit and run (even thunderfire cannons, lol). Charging a unit of bikers with spawn is often just like handing them an express ticket to where they want to go.
2. There is a Supercuts about 15 minutes from battlegrounds. if you get the bye, getting a haircut is a good way to kill about an hour.
3. There are some really crazy death stars out there. Run away from them. I charged Mike's "SpiritSeerStar" with a great unclean one (iron arm, warp speed, rage, rampage), a daemon prince, a soul grinder, a chaos lord, and 3 spawn, in 1 turn, and on the charge turn I killed 1 drone and 1 wraithguard, or something like that