"Can someone whose a huge vinyl fan establish a case for SACD as well" Yup,WITHOUT A shadow of a doubt.!!!!Once your set-up is up to the mark,the Quality of the recordings become more important than the format..I fully agree with Mikelavigne about the superiority of DSD recordings.This has been my experience too...
"I've 8 or so SACD discs that I've played via my Sony BR player that didn't sound much different than standard digital, but granted that playback was observed through my HT only " yup,you are right there.Bring those SACDs{I hope they are one of those 'proper'SACDs ,not a mimicker]to a properly set-up SACD rigs and hear the difference!!!
"I've 8 or so SACD discs that I've played via my Sony BR player that didn't sound much different than standard digital, but granted that playback was observed through my HT only " yup,you are right there.Bring those SACDs{I hope they are one of those 'proper'SACDs ,not a mimicker]to a properly set-up SACD rigs and hear the difference!!!