I feel the tyrant's price is very justifiable. He's got awesome support powers and can still handle himself in most all situations.
Pyrovores... are just an embarassing codex entry. Musta been cruddance's last minute bug. I honestly think the model was meant to be an advanced biovore artillary bug or something... I mean it doesn't even look like a flamethrower/acidspitter thing. At least they could have made it fire like a hellhound and a make it look like its arcing it's shot... or something.
I think the tyranid elite section suffers from the same sickness the CSM codex's heavy support does. Where one or two choices far outweigh all the others. No matter how cool some of the others are... I'm looking at you venomthropes..