I like the font treatment on Entry #18. And I like the color in the elipse shapes. Go ahead and remove the tagline. I'm not sure it's needed. I like how the abstract elipse shapes, but I feel like it looks like a hat. Could you possibly change what is around the diamond? Maybe use some flourishes around the diamond and still have lines coming out the right and left side.
Could I see a version of yours with the "O" as a diamond ring? Maybe not so literal but somewhat abstract?
Hi with respect to "Trinova" this concept was his first submitted if it is the clients request from the logo to be designed please inform him also thanks ^_^