Copper to pex

So I have searched and havent found any definitive answers regarding the quality of pex fittings vs sweating copper. Doing a bath remodel and wondering if you guys can steer me in the right direction. Have shower lines (no tub), toilet and sink. All currently copper running from the floor up, and replacing the shutoff valves and lines above those. Would you recommend to replace with new copper or are pex lines and fittings sufficient, and would they last? Also what would be the best fitting to use that would have the least amount of chance of leaking? Thanks