I don't know why I waited so long to get these things. They are so cool. When I first started my Zendala, I didn't like it, but once I finished it by adding shading and a few more details, I really love it. Most of the work is done with my .005 as I wanted a delicate feel.
Finally, I just had to do the Diva Challenge on a Zendala tile, too. The challenge was to use Hybred with the Strircles tangle-enhance. I'm still in a spiral groove and that so fits the new round tiles. My first attempt fell a bit flat, so I added the DARK stripes in what was previously empty space. It certainly changed the feel. In an unexpected and not quite desired way. But that sort of surprise is the fun of Zentangle®.