Input levels on the Mk1s were giving people issues with hotter signals, so those inputs were upgraded along with the encoders/screen etc
The Mk1 Input handles +8dBu (5.5V peak to peak)
+17dBu for Mk2 (15.5V peak to peak)
sure sounds more convenient, but does that result in folk experiencing/perceiving samples which sound more underwhelming (due to loss of level relative to imported samples)