I am not sure what the advantages are to an intermedate camera is. I have never owned one. But to me the advantages to the DSLR are, more control of the final image. Just shooting in RAW format and haveing that much control alone. Also a DSLR will hold it's value longer and sense you are buying a system when you upgrade most times you keep the lenes and just upgrade the body. I am also not sure that you can use filters on intermedate cameras. Once you make the plunge you won't look back.
Greg