Banshees are pretty much the hardest to maintain/get out of combat out of any of the melee units. (I'm sure anyone who played agrees). Once their shield goes down, they seem to almost always get slowed and cut to shreds, which is usually when they actually need a 'speed burst' to escape.
The problem is Assault Space Marines have so many things they can do and they remain useful throughout the game, and even cheaper BoyZ can do their melee job well especially when launched/supported by Truks. On the other end Banshees who need to maintain their weaker shields are usually glued in to die.
That brings me to the QuickStrike vs Assault Leap. The damage and all is where it should be, but the other aspects are all underpowered.. (even considering the basic ASM leap whichis basically 'teleport' and makes cover fairly useless against them).
- -takes at least a second to 'wind up'
- +does more damage through units it passes through
- -cost 75 req and 40 energy
- -cost 175req and 25 energy + about 2 minutes of building upgrade structure first
- -slower movement , even somewhat laughably dodgable
- -can be 'canceled' or 'wasted' if stunned
- -does little or no useful damage to units it passes through
- +cost nothing, just a free doctrine
- +allows ASM to run away in situations that Banshees are screwed
- +allows ASM a 'secondary' leap where if bolters are revealed, or they are chasing etc. they can just offensively leap to location
- +faster movement
- +cannot be 'canceled' or 'wasted' even if stunned
results: Assault Leap (6) vs QuickStrike (1)
For a fairly mandatory ability, QuickStrike is woefully late to research, cost resources, and doesn't even have as much effect as just spamming ASM or BoyZ with their right support/doctrines.