1500pt Astronomicon w/Vect

As seen here

Vect seems popular (there's a 1750pt version with 3 ravagers, incubi, vect+dias+court) for tournaments. I wonder if it is in part due to his sieze on 4+ that can screw people royally along with an accurate low ap blast?

I'm thinking of getting another venom and a cronos to make this list as it looks decent! Thoughts - it is a bit venomspammy but also makes up for the pain tokens with the chronos.

However **IS** vect worth 250 of 1500 pts?

Ive made a list with him at 1500pts. But you really cant afford the dias IMO.

I realise a dias is excessive at 1500 but vect himself actually seems viable. However I have no idea how I'd actually use him - stick him with some wyches and aim at the nastiest unit?

That sounds like a dead unit. You could always toss him in a unit of incubi in a venom i suppose.
Vect himself can be made viable as long as he gets into combat which is where he'll dominate most opponents and squads. His rule allowing him to sieze on a 4+ is pretty damn useful. You just need to be confident you can get the most out of him as otherwise he's a very expensive hole which could perhaps have been filled in a better way

If you're gonna run vect, it's worth the points to up your wyches to BB's... the extra wych weapons are worth their weight in gold, and since you only have to run 9 BB's instead of 10 (for max wych weapons/unit) all you're paying is 2 points (If i remember correctly) for an extra LD and A. When you pair that with Vect, you're looking at some really nasty killiness. I've run that deathstar a good few times, and it always does well. I can't think of a single time where it didn't earn, at least, its points back.