So I ran Vect over the weekend in some campaign games, a few with the Dais and a few without. Here are my thoughts.
I was impressed with Vect himself, who i ran with 8 wyches (agonzier, hydra) and a Haemonculi (agonizer, liq, scissorhand). He is a pure beast in combat and wiped out squads of marines. I found the orbs to be ok, but most times I needed to fleet to get him to avoid the powerfist sgt. The 4+ sieze is ok, useful but not awesomely powerful.
I ran him in a raider and the Dais to see just how bad it is. The campaign rules even meant I could make it venerable, yet still it sucked. Lack of arial assault and flicker field really hurt it, and it actually went down to a glancing plasma gun shot.
Is Vect worth running? Yes and no. I missed the Dukes buffs to my wyches (4 squads) and the fact he can sit back in his venom. While Vect does damage you still have to get him into combat with something worthy, which can be tough when riding a paper plane. If he gets shot down early you really feel his heavy point sink status on the game. As for a ride, Venom or raider im on the fence, but the Dais is a definite no-no.
His tricks are average, with the 4+ being useful. It's tempting to gamble on it with deployment bluffs, but will hurt if it fails. The orbs are nice and will kill marines, plus help him take allocated wounds as he can get them back. But lack of eternal warrior means you often have to get around the hidden fists by using fleet.
Vect 7 out of 10
Dais of Destruction 0 out of 10
Dark Eldar 2k, Space Wolves 3k, Raven Guard 3k