Are new Mark Levinson Preamps better than old?

Thank you for your comments.  I know Levinson gear was legendary in the 1980s and 1990s, and I have been lucky with my two units from the 1990s: the ML 380 preamp I mentioned and my ML 332 power amp, each of which I have had repaired only once.  As I said, I am thinking of upgrading at least the preamp, but the two issues that I need information on are: do new Levinson products sound noticeably better, and are they as reliable?  I would have thought that 27 years of technological progress would offer better sound, but so far it sounds like it may not be a great idea.  If anyone else can provide more information, I would appreciate it.  I don't want to part with that kind of money and have no noticeable improvement.

willcycle - did you ever hear the difference between the ML 380 and your ML 380S?  I wish I had purchased a a ML 380S all those years ago, but it was too costly for me at that time, and if I were to get one used it would be as old as my ML 380, so it would have to really bring better sound to be worth it.

triwhiz - thanks for the info on the ML 526.  I actually have an ML 5101, and I am very happy with it.  Since I already have the ML 5101 DAC and since I do not listen to vinyl, do you think the ML 523 would work as well?