Have there been any major changes to the slc family since 2015 or are they all the same? Also how is swarovski handling the warranty going forward on slc models now they have been discontinued?

Looking at a used pair of 2019s and just trying to answer the last 2 questions in the back of my head before I buy and I can't seem to find any info online.

Service is with SONUS North America. They should be fine with no problems. Kahles is going to build a version of the SLC starting this Summer.

True, though not available in the USA.