Comment on Prism

And I say to you, dear Reader, my experience that this videoconverter cannot make high-quality any videoformats indeed. But it is true that I maybe have few knowledge about it. For example MPEG Streamclip can make high-quality videoformats. But why cannot Prism do? Therefore I ask You because I have bought Prism, I thought it will be good. But not. Can You help me how to do, etc. Thanks.