It doesn't matter how long it was on screen, it's the fact that it DID happen and it's the first impressions that count. I also don't know at what elevation Sparks was when he unscrewed the back of Buzz! So take that! Plus, as you pointed out, Sparks lacks the lights in his eyes that really make him look the way he does. So for right now, Sparks is a DEFINITE pass.
And yes, Twitch did have a staff and he DID use it in the film several times but he was also without it several times so it's passable. I could always MAKE twitch a staff and it'd be tolerable.
Sparks though... not forgiven.