I read that the only upgrades made to the ports of 3 and 4 were 108p, 60fps, and "a lighting upgrade". What do they mean by that? Do the games use HDR now or is there better lens flare? I am just curious...
It's exactly what it says on the tin. The lightning engine and enhanced textures was the only things remastered in 3 and 4 to make lighting, shadows, reflections, and some objects look a bit better.
you can see a comparison video here
It's not really very noticeable while playing, but side-by-side it shows.