"3 flat in several months"... you have not found whatever is causing the flats. Independent of flats, I often carefully inspect tires looking for glass, wires or other bad stuff and remove it with a pick. It helps, have not had a flat in more than 4000 miles of loaded touring. I more often check tires when in area of high road debris (cities). Energizers are lower level, Marathon provide best flat protection, so go with marathons. Tubeless is worth considering if in goathead country, otherwise it just another messy complication.