I am planning to build a log home in New Brunswick, Canada in the summer and use PWF Foundation SIP on concrete footings. The diagrams I downloaded from their site showed a plywood floor made with ridgid insulation between 2X4 sleeper with a plywood subfloor.

This is a new idea for me and was wondering if anyone had experience with it as apposed to a concrete floor.

PWF floor systems have been around as long as PWF walls. We actually used one here in KY about 15 years ago with an ICF wall system. To my knowledge it works just fine. The key is lots of clean wash rock fill under the floor system with drains to divert groundwater. And a double layer of 6 mill poly with seams taped under the floor system. Our system used 2x4 sleepers on the rock, then the poly, then 2x6 floor joists and 3/4" plywood, all .6 retention CCA PT.