My first flight with LOT was in 1970, a 3 US$ student ticket on a domestic flight. Since that time LOT has improved a lot.
This year I flew LOT domestic and European, both C and Y class. Here are my impressions.
Check-in agents and airport staff : Correct, nothing fancy;
Lounge at Warsaw : Not the top, but good service and well maintained, all drinks, papers, etc.
Boarding : Normal European way, no pre-boarding.
Inflight service : Excellent, very efficient, cabin staff masters languages, is friendly and sincere. You really get the feeling they take care of you, in particular in C;
Cabin : clean and well maintained;
Metal : relative new fleet, Boeing etc., well maintained.
Food : fair/good, as good as most European airlines. Kosher meal served. In general LOT can indeed spend more quality effort on food.
I will fly LOT again.