Yes - if you update the Speed 1st, you're fine.
If you do Spd, Atk, Atk, Spd... RESET.
If you do Atk Spd... RESET
After the first Speed bump, the second and third are not worth it.
2 Seconds -> 1.8 Seconds (-10%)
1.8 -> 1.764 s (-2%)
1.764 -> 1.729 s (-2%)
I just typically upgrade the damage, for a better "alpha strike" trying to 1-Shot enemies :P