When I have time I also do enjoy taking local service trains, not express trains. Local service trains can have 5 – 10 min. stops at a station in country side. Reminds me that occasionally need to slow down and smell roses. I do not think those long stops at stations is something to be warned about. Train schedule is out there in public, we know when the train supposed to arrive at a destination station. As in many situations in Japan, the train will arrive on time as schedule, nothing to be concerned about.