I'm not sure that digital is a waste of time without multichannel, but it is true that MC is the greatest factor for improvement over analog (for us poor guys who don't have $80,000 LP playback gear). In particular, for someone who will not install multichannel equipment, I doubt that SACD or DVDA is a big upgrade over CD.
I have many 2-channel discs and LPs, and have experimented with many of the matrix systems that can derive multichannel from a stereo source. Almost always I find the result problematical. There is a compromise however, three (not five) channel, and there is a product (SST Trinaural Processor) that "Blows Away" (sorry about that) all the other systems. You can read my review here or at the Imperii Audio website. Kal also had a favorable review in our favorite rag.
I have many 2-channel discs and LPs, and have experimented with many of the matrix systems that can derive multichannel from a stereo source. Almost always I find the result problematical. There is a compromise however, three (not five) channel, and there is a product (SST Trinaural Processor) that "Blows Away" (sorry about that) all the other systems. You can read my review here or at the Imperii Audio website. Kal also had a favorable review in our favorite rag.