It is a very lovely banner: 7/10
The things I can see constructively is since the sub-headline is like that it creates an open void to the side and makes it seem more boxed it. It is true it is a banner and supposed to be a rectangle but it is just the fluency. I like the sparks of color in the background, a lovely touch. As for the boarder this all just depends on the person xD I'm just not one for thick boarders but it dosent necessarily draw away from the banner.
The colors match quite nicely and it is not to cluttered
smile