I can't speak to the Nationals pattern, but this is a great ball for playing up the outside -- especially when the pattern breaks down. I like to think of the Blackout as urethane on steroids: all the control, smoothness, and predictability of urethane with the carry of a reactive ball.
Like you, I am a slower speed bowler with low revs. For guys like us, this ball is a secret weapon. When all the crankers are standing in front of the gutter we can move right and have a line all to ourselves.
I put a weak drill on mine (9 o'clock) and put it at 1000 grit paper plus polish.