Those are the same two pads I'm considering. Here in the Ohio-Kentucky-Indiana area, an R-3.4 should be plenty for 3 seasons, and I was thinking a Z-rest under it for winter. I'm leaning toward the Trail Scout because I find the solid-core foam more supportive in thinner pads - but I'm not sure how stiff it will need to be inflated to provide adequate support. I've got past experience with Prolite Plus, and it was always comfortable enough - but I think they use a different foam now.