I do lots of touring, and ride all year long as I am car-free. I run Schwalbe Marathon Plus's and never ever get flats. I hate flats, I love my SM plus's.
But in a few months, I am going to being the first of my brevet series for this years randonneuring program. My plan is to switch out the SM plus's (38mm) for Schwalbe Kevlar slicks (35mm).
Question one: Will the rolling resistance be noticeably diminished, allowing me to roll faster and easier?
Question two: Will the Kevlar tires be just as effective at preventing flats?
I am a good rider, and I watch out for glass and such and don't take unnecessary risks while riding. Have I mention I detest flats?