I'm interested in other opinions on this as well.
Here's a video comparing some coatings including POR-15 that might be of interest to you
https://www.youtube.com/watch?v=oBOAkpujGBM
I think I'm just going to stick with SPI epoxy on properly prepared surfaces unless I'm convinced otherwise
https://www.southernpolyurethanes.com/epoxy-primer