A bit of mild sharing, I played the Tantalus yesterday.
I'd just finished building it so wanted it to have a decent first outing, so brought it to bear against some Imperial Fists. And their Skyhammer.
I will, off the bat, admit that I played it quite cheesily.
I took the Tantalus, and put onboard it an Archon with Webway Portal, and 9 Medusae.
Because why wouldn't you.
This comes in at a frightening 535 points, and thats not adding anything else to the Archon to make him slightly more useful (I did add extras - namely a Blaster).
And it stole the show.
Granted I was playing it in a very anti-Marine capacity, with those disintegrators and all that AP3 template weaponry.
It dropped in turn two thankfully while I still had other stuff on the board.
My army was already taking a beating to the Skyhammer, so I dropped the Tantalus right in the middle of all of it.
Straight off, the Medusae obliterated an Assault Squad, and the Pulse-Disintegrators crippled a Devestator squad.
The other Devastators unfortunately were Grav weapons, and little use, so when turn two came around, I did the exact same thing to the remaining units.
Then turn three turned its attention to the Command Squad.
So by the end of turn three, this 535pt unit managed to wipe away somewhere between 800 and 900pts of Space Marines.
It truly was a sight to behold.
The Tantalus = worth it.