Looking at the examples you posted, it looks to me like they are all openGL renders. Your file sizes,being as small as they are and the very short render times reveal this also.You may want to try using another rendering engine or program like Vray or some more sophisticated program. If you have tried the 3d delight render engine that comes with Daz you certainly would not have pixelited jagged edges, but more like smoothed vector edges. Even so, I had this same problem in the beginning because all I was aware of was OpenGL and preview renders. What I did was I opened the finished .jpg up in photoshop and enlarged it greaty and using the smudge tool (with a very small setting) manually smoothed out all the jagged edges. When I sized it back down to original size it was smooth as silk and looked great. Surely not the way to do things right,but it may help until you can pinpoint the problem. Anyway,these examples really look like openGL preview images to me.