I havent tested omega much, but the thing is omega=great directdraw, powerdraw=great 2D through Direct3D, if you dont mind having a 163kb dll with your project and dont aim for lower end hardware, powerdraw is better. Basically powerdraw does most things through hardware so it has lots of advantages like almost free texture filtering and effects with alpha which would be slow in software are quite fast with powerdraw. Like Lifepower said check out some particle demos which came with powerdraw and see for yourself.