Ok, after playing six games of Grey Knights in 6th ed, even I have to admit this. Psybolt ammo is pretty busted.
My list?
Brother Champ w/ Psybolt and Brain mines.
Ven Dread Psyfleman
Dread w/ LC/ML
10 man strike squad w/psybolt and 2 psycannons
10 man termies w/ psybolt and 2 psycannons
LRC w/ psybolt and multimelta
Opponents:
1st opponent: Space Wolves Grimnar Wing: Tabled him. Only Lost my LRC to Grimnar in hth.
2nd opponent: Deathwing, one 5 man squad of Deathwing termies standing at the end. Took 3 table quarters, only lost LRC and Brother Champ in hth. Lost the game because the 5 man squad held the only 1 objective and game ended on turn 5.
3rd opponent: Eldar. Only Dark reapers, Farseer, and Dire avengers left standing. Only lost heavy dreadnaught. Lost the game because Dire Avengers sat on 2 objectives to my one and game ended on turn 5.
4th opponent: Grey Knights vs Grey Knights, I lost due to first blood and slay the warlord. Lost Termies and Brother Champ in hth.
5th opponent: Dark Eldar Tabled him, only lost the Ven Dreadnaught
6th opponent: New Chaos Tzeentch 1k Sons. Took 3 objectives to his one. Did not lose a single unit. Killed 1 Defiler, 2 rhinos, 1 squad of 1k sons, 1 squad chaos termies, and 1 chaos predator.
It was pretty gruesome.
The Ven Psyfleman pumps out pain to any light vehicle/MC/walker at a massive distance, the other dreadnaught backs him up. An effective 54" threat radius at full efficiency for both dreadnaughts.
The LRC with Psybolt is a beast by himself. The new 6th ed rules for vehicles may hurt light tanks, but the LRC is now a real beast. Psybolt everything make it pretty beardy. Anything within 30" gets hurt. Anything within 12" eats 17 shots. Plus it's an assault vehicle, plus it can ignore certain effects, plus massive armor, plus POTMS, plus...
Warpquake puts a serious crimp on any deepstrike shenanigans. Forced Grimnar Wing to deep strike way away from me, where I picked him off piecemeal with psybolt/psycannon death.
Pre-measuring takes shooting to the next level. GK end up having an effective threat radius of 30". That's massive.
Rhinos, Raiders, and Ravagers just crumple to psybolt/psycannon shots. Easy first blood points.
Pre-measuring w/ deepstrike and forgiving dangerous terrain rules make deep-striking GK termies very effective. They just appear out of nowhere and start ruining units with shooting. Opponents end up dedicating their entire army to deal with the 10 man squad, leaving the rest of my army alone. And GK termies are scoring without requiring a pesky special character.
Vanilla Brother Champ is a steal at his points cost. He can shut down and "one shot" characters in hth.
Still have yet to face a true horde army , nids, Orks, or IG. Plus I hear Necron Scythe-wing lists are pretty rough.
My fear is that someone at GW will wise up and nerf GK and their psybolt goodies. Seriously, every GK marine effectively has a heavy bolter + relentless +excellent hth. Somethings going to happen.
Eldar had their starcannons nerfed, GW nerfed the Fantasy powerscroll with 1 FAQ. it can happen.