Great to see this list being discussed; I love it. I've been running a very similar list with great success in my little local meta. I run:
Juggerlord w/Axe of Fury + 5 bikers w/2 melts
3 Spawn
Heldrake
Maulerfiend
Vindicator
Oblit
Vendetta
IG command squad with 4 plasmas in a chimera with heavy flamer
manticore
All of the above is a turn 2 threat which is all flimsy on a unit by unit basis, but overall adds up to threat overload. The manticore never does much but forces my opponents to go after it in order to prevent long term damage. And its there to reach out & score first blood on something.
I also run a cultist squad, Plague Marines & a plague lord on palanquin to provide backfield protection for the manticore. The lord is my Warlord and with 5 wounds, T5 + Sigil hopefully will keep my opponent from scoring Warlord point.
The secret to the list and yes, I say this seriously, is the
IG troop choice: Penal Legion. Yeah, yeah, I know they suck, but they keep the list fun. During the heyday of aegis defense lines, they would outflank and grab a quad gun in half my games against aegis defense lines. It was great. Or they would outflank in front of the wall & go to ground for a 2+ save. They can also just hide out somewhere & score line breaker.
The local meta has been swamped with Tau lately, but with most of my units across the board by turn 2, I've been able to keep most games close & win more than lose.
I've been thinking of adding Noise Marines to deal with biker spam, but that's just an idea at this point.
Similar list was discussed here:
http://www.imperiusdominatus.com/2013/04/e-mail-csmig-1850.html