I just picked up a B/G Centaur (from Krumpy actually). I throw it a good 5-7 boards of where i throw my Charcoal Ex. I also throw it more down and in too. I'm not a senior but, I throw the ball around 15.5 mph. I got it as a light oil ball and it has filled the bill exactly.
The other option you might consider if you can find one is a Slate Blue Gargoyle. Visionary discontinued this one but, it was their other light oil ball.
Just my $0.02
Mark