Youzign: My take on it after several months use
When it was released there was huge amount of interest generated by a great marketing campaign. In many cases this can hype a product beyond expectations.
I have used the product mainly to create graphics for ads such as Facebook and for artwork for my blogs. It is quick produce reasonable edits and add to existing pictures. I do not have the template library upgrade as I did not see the need when starting and cannot comment.
Source: Youzign | You are the designer
For me Youzign is good for quick editing and production of graphics. I do have some issues. You cannot create 3D images such as those seen in e-book ads. By this I mean pull in a 2d picture add and edit text then generate an image. You can create a pseudo image but have no control over the output as it is a template. To do this you would have to revert to Photoshop. The background removal tool is not intuitive to me and I still find it difficult to get good results.
Apart from that I am using it all the time for my work and it is definitely worth having.