12 bit compressed NEF vs. JPEG

So I am a newly converted Nikon shooter (D800) coming from Canon and I have some questions regarding the raw options of the D800.

I'm a landscape/architectural photographer along with shooting a few weddings a year. I'm going to transition slowly from Canon to Nikon by shooting both for the first 2 or 3 this year. My usual shooting method was to shoot in sRaw to have more editing control compared to JPEG while not getting too excessive on memory space.

So my questions, how much information is lost when shooting in NEF 12 bit compressed? I'm assuming this is still preferred over shooting JPEG, correct? Is there much file size difference between 12 bit compressed vs. 14 bit compressed?

Thanks!