It depends on how confident you are with both routines; patter and mannerisms included. Both are great effects. I'm more familiar with 'Optics and I think that, only going off the effect, would be a great day 1 go.
If I have this right, your talent show is comprised of 2 'rounds' set three days apart. I think you need something strong and visual to get you in the door and 'Optics can do that. Day two's Wordsmyth. Your foot is already in the door. Everyone knows that 'you're the magician'. So knock 'em dead with Wordsmyth. It's very spectator involved, but the effect is a bit...quieter and not as in your face than Optics. If that makes sense.
In short, use Optics to build rapport. Use Wordsmyth to put you ahead in day two.
If I have this wrong, let me know. But I think it would help if you clarified how the mechanics of your talent show works. Such as: why is it split up? Is the day 1 a qualifying round? Are there prizes up for grabs?
Details.