Interesting but this seems like it makes attacks with special effects potentially much more powerful that standard maneuvers.
For 5 shifts of power an attack with a special effect can do damage AND place an aspect that the target can only escape from by rolling a 5 on an appropriate skill. If the target has a bad skill, the maneuver can last a very long time, and they have to use their action to remove it.
With a standard maneuver 5 point of power (against a target with a target attribute of 3 or less) will have the effect last for 3 exchanges and do no damage.
I'm not sure it's that bad:
"These weapons [stun guns, tazers, tranc darts, some poisons] should still get ratings based on the guidelines given in Playing the Game (page 202), but instead of applying the Weapon rating as stress on an attack, the attacker might instead opt to impose a temporary aspect on the target (as though he'd performed a maneuver) in addition to the stress from the attack roll... [nets] can have their ratings sacrificed to enter the target in a grapple...
In either case, rolls to overcome these secondary effects are made against the weapon's rating; use the rating as the basis for rolling the opposition -- i.e., Weapon:2 = Fair (+2)" (YS 326)
So it sounds like the caster has to commit to a Weapon Rating for the spell, just like a tranqulizer gun has to have a Weapon Rating even if it is only meant to knock out its target or achieve some other Special Effect. Wish I had found this section when I was trying to model tranq guns!
If I understand it correctly, it means that for such an attack option, it doesn't matter what the Weapon rating is (even as low as Weapon:1), it still places the Aspect if successful, but the target rolls against the Weapon rating itself, not the final roll.
Or would the attacker's Weapon + shifts have to equal at least 3 to place the Aspect?