I think you need a little practice. I would not say to never use a border. Sometimes they do look very good depending on how you use them. You say your getting bashed about your flow. I think this time you made your render and the surrounding's flow a bit to much. Its hard to distinct between your render and your background. Also you should try using a better focal point for your render. The sides tend to side track the effect of the image thus, eliminating the "soothing" effect to another persons eyes. I have a tutorial somewhere on my computer about focal points and creating good signatures that flow and it also teaches you how to match your render color with another color to allow it to have a good flow. When I find it I will post the link here. But, overall your getting there...
