First, I love the log cabin - the dark/like contrast is really striking.
OK, back to your borders. It does look like there is some fullness still in the borders.
Can you post a pic of the miter? While the miter looks flat, it doesn't quite look like it's at 90 degrees, so I'd like to see a close-up looking down on it (before I do anything drastic like suggesting you redo the borders). ;-)
The turquoise really works - gives the top a real sparkle.
Is this a gift, a throw for the den? What's the plan?