I tried out a Stormraven with a twin-linked heavy bolter, twin-linked assault cannon, hurricane bolters, and psybolt ammunition the other day as an air superiority fighter, and I must say, this is a fun toy.
4 S6 Rending, 3 S6, and 6 or 12 S5 shots, all at BS4 with a re-roll to hit. Hull points simply disappear. Granted, I was up against AV 10/11 dark eldar flyers, but it was still very effective. My raven took down two voidravens before it started gunning for light/medium infantry.
Mathammer:
AV10 over 12": 2.96 pen/1.92 glance
AV10 under 12": 3.84 pen/2.81 glance
AV11 over 12": 1.04 pen/1.93 glance
AV11 under 12": 1.04 pen/2.82 glance
AV12: 0.59 pen/ 0.44 glance
I didn't factor in missiles, as I play Grey Knights and our missiles are a joke. Blood Angels would certainly have the option of firing missile instead of using the hurricane bolters when presented with Valks and other StormRavens.
Granted, mind strikes have gotten a lot better against certain opponents, since perils doesn't get a save anymore. Fire off all four to insta-gib hive tyrants.