The mark is nice, Id like to see an execution that simplifies it and makes it more more obvious this is a Z. How can you make sure the Z will legible at small sizes and in greyscale only. I think you can push this to simplify it and make it more elegant.
getting cleaner, thanks! can you make the diagonal in the z connected like in the first execution...the droplet effect is nice, but need it to be more graphic/simple. See how this logo has varied levels of connection between the dots? I think you can do the same with this mark: http://zeobit.com/
on 50: Its a strong mark. what would this look like if the heads (circles) were moved away from the linking arms a bit and you removed the depression the circles make?