True Blue is a fine round powder. "Unflattened ball" vs "flattened ball" as it were. It meters superbly. It is one on the least position sensitive powders at low pressure I have tried. I have not loaded it light enough to experience the "muzzle blast like a coal burning locomotive" 1SOW mentioned. I have loaded it at full pressure in 9MM, where it works well, and in .45 Colt, where pressures are fairly low. At both levels it has burned cleanly. I have also tried it in .32 ACP, .38 Spl, 5.7X28, & .40 as well. Overall my impression is positive.
ZIp is about as close to W-231 as you can get. It is very accurate in low pressure .45 ACP. I have not tried it in 9MM.