Yes, S.A. 3 has good damage potential and combos easily, but using her ES moves consistantly in battle (using S.A. 1) outweighs the damage of S.A.3, imo.
A good example of this would be using the following combo :
j.JP, j.FP, FK xx ES Tsumuji (qcb+2K)
Does 70 damage to Akuma (gouki) with default damage/diffaculty.
j.JP, j.FP, FK xx Yami Shigure (qcf, qcf+JP)
Does 87 damage to Akuma (gouki) with default damage/diffaculty.
With a max bar in S.A. 1, she can store up to 6 ES moves. In S.A. 3 she can only store 2. And since any cancelable normal move can be followed up with an ES Tsumuji, it makes having a lot of energy very useful. Any time you don’t have enough energy, you’re probably better off with a Raida.
S.A.1 also does incredible tick/block damage which should not be overlooked.