Did a game versus the Iron Warriors of Saukopfblende several weeks ago. Admittedly, we used this game as a testing run for a 1.500 pts 'Midigeddon' Tournament (120x120 table, just 2 Objectives).
I played Ulthwé (4.2) and fielded:
AVATAR [free]
Avatar with Spear of Khaine
WRAITHGATE [50]
BLACK GUARDIAN WARHOST [325, BTS]
2 Farseer, 6 Guardians,+4 Guardians, +2 Wraithguard
BLACK GUARDIAN WARHOST [275]
Seer Council, Farseer, 4 Guardians, 2 Heavy Weapon Platforms
SWORDS OF VAUL TROUPE [250]
3 Falcon, 2 Firestorm
ENGINE OF VAUL TROUPE [250]
Storm Serpent
ENGINE OF VAUL TROUPE [250]
Scorpion
RANGER TROUPE [100]
4 Rangers
Saukopfblende had:
Retinue with 6 Chaos Marines, 2 Havocs, 4 Rhinos
Choosen with Rhinos
6 Defilers (BTS)
4 Chaos Predator (played with 5+ RA), Stalker
4 Chaos Basilisks
The game was more or less decided in Turn 1. I had absolutely nothing to engage the well deployed Basilik battery which pounded my position with brutal efficiency. I remember the 6 Defilers doubling into a wood before sniping my covered Falcons, breaking them in Turn 1 before beeing activated with some lucky shots on 6+. The Choosen succesfully shot down my moved up Storm Serpent (Critical Hit). I failed to rally the reamining 3 Falcons, denying me further offensive actions. What followed was a do or die charge out of the Wraithgate of my big Guardian Host with Wraithguard. I did beat the Defilers, killing 5 of them, under heavy losses, but them being fearless one got away unharmed. I tried to snipe it with my Scorpion but missed both shots (failed BTS). Saukopfblende then pounded my massed Guardians in the open with his double template Basiliks and managed to succesfully wipe the formation out with Bolter fire of the Predators. He took the Wraithgate objective and had BTS. My Rangers killed some Chaos Marines with Overwatch but finally couldn't hold on to the objective. Lost 3-0.
My impression was, that while the Iron Warriors clearly need something to compensate for not being able to summon demons, 6 Defilers are very strong, especially as a fearless BTS. The Basiliks battery at 4 untis is a bit over the top at 325. Well, that's a double template, auto activate, break only at 2 losses formation with effectively unlimited Range at Strat 4. Who could resist taking them?
Well, hope that did help you a bit.
Cheers!
Fenvarien