Splinter - the one minor issue I had with the WB bladder is that there was a seam that crossed the opening where I had cut it open. I was losing vacuum there due to the double thickness seam. I found that a little butyl tape applied there fixed the issue.
Pottz - I should have pulled the veneer pieces apart slightly to reveal the gap. Even staring at the original hi-res image I have some trouble finding the seam. I'd say that's a winning jointing technique.