It is more corrosive than black powder. It works fine but I don't care for it. A fellow on another forum did a test using BP, Pyrodex, and Triple 7 burning them and leaving it in the garage for several days. T7 was nearly pristine, BP was a little pitted, but Pyrodex looked as though it was soaked in acid.
If you find yourself without the time to clean it up soon after shooting you can use Ballistol to give you time. It saturates the fouling so that it cannot absorb moisture. I've tested this by leaving my pistol in my Texas garage where humidity levels are extremely high.