"PEX tubing is a lot less likely to burst if it freezes than copper"
"AND it never breaks in a easy repair spot"
I have PEX piping in the cabin 70 miles outside of Los Anchorage. Having failed to drain the water system completely a time or two prior to Halloween (go-by date for winter), I can attest that both of the above are true...although compared to a break in RV piping, almost anywhere in the cabin is an easy fix spot.