Magic Tricks

This is a cool idea. The effect of a cane appearing where a marker just was is a good effect and lends itself to a little bit of comedy before and after the appearance; but it's not going to fill time in your show, it's not going to be the thing everyone talks about the next day and it's not likely to be your new favorite thing. It's a novelty and good for a quick, unexpected, eye-catching appearance and a little comedy.

I have a friend who is using this in his show and playing with it after one of his shows is what convinced me to buy one. The first one I got arrived broken. It never opened properly, (flopped open/down at the top), and setting it to its proper position and storing it open and untouched for several days to try to reset its "memory" failed to work. The replacement I received works just fine.
Like I said, it's a novelty thing. Good for an immediate, unexpected appearance for which you will get a few gasps or slight jumps from your audience and you should be able to write some humor into your presentation before and after the appearance.
Three stars - middle of the road. It's not your next great piece, but with the right application, you should have fun with it.