I had absolutely no problems with the radio/navigation systems in the 2011 and 2015. They were easy to use while driving because the touch screen and buttons worked flawlessly. I often wish the 2019 had the same system as the earlier cars. The 2019 touch screen is sensitive and does not always respond the same to touching and the volume/tuning knob problems may be common (based upon threads here).
Gerry
Silver LEAF 2011 SL rear ended (totaled) by in-attentive driver 1/4/2015 at 50,422 miles
Silver LEAF 2015 SL purchased 2/7/2015; traded 8/10/2019 at 82,436 miles
White LEAF 2019 SL Plus purchased 8/10/2019