Well, I really think the Tonic is going to be a nuisance to try to read. If the whole point is to be able to reliably cut very small increments off CS, then you have to be able to read the increments. So I am sending the Tonic back (free shipping both ways so no loss there), and I ordered the SU guillotine at the sale price, which was only a few dollars more than the Tonic was.
I'll use my trimmer exchange for something else. I just wish SU offered credits. Maybe if you're a demo they do. But I'm not a demo and I don't work through one anymore, not since my SIL let her demo status lapse.
But I did open up and try the Tonic, and I get why it's better for some things than a track-blade trimmer.