Bullcrap. There's debate, I'm debating it right now. Yeah, you can crash.....most of the time you don't. T6 and something you can only hit on 6's is pretty awesome.
Dude in the top bracket at Battle For Salvation was running dual flyrants. Mike Bryant won the second Braket with his tyranids (no flyrants, though).
I weeped for tyranids before, in 5th, but I am done now! Your army is good, Keith, rejoice! You need be emo no longer.