People have asked a similar question in the past, and I believe the consensus was "it depends". Sometimes the remasters are done on excellent equipment by very competent people who really care about the music. Sometimes it's marketing.
The new digital technology is an improvemnt over the old. A current well done remaster should sound better than an old MFSL CD, just as the newer MFSL CDs should sound better than their old ones. Whether or not a new well done mass market remaster sounds better than a new MFSL, XRCD, or DCC disc probably depends on your personal preference.
Manufacturing also comes into play. MFSL, XRCD, DCC, etc. are all made in small batches and quality control should be high. After all, that's what you're paying for when you buy their CDs. Some mass produced CDs are made in plants that do a better job than others. I read an article written by the guy who mastered the last Steely Dan CD (I think), and how the poor manufacturing actually changed the sound. He had to figure out what caused the problem before okaying the production.
So..."it depends".
