I had that set-up on my last bike, won't do it again. It was a good solid bag, thick leather with a inner rain flap. I also did like dog33 did and used Sno Seal. Main problem was that it got filthy with minimal riding, especially in the rain, or just wet roads. If you didn't have gloves on when you opened it, hands would by just as dirty.
I'm back to a bag on the front forks, for good.
