Forza Apex is a DX12-only game (and UWP to boot!) and it runs beautifully on my PC, which is amazing considering it's a beta. I'm super excited for the full version and will buy it day one.
You haven't been paying attention to DOOM if you think there are better looking engines than it. A lot has to do with the art direct and animators, of course, but... What other engine has the same type of particle system as DOOM, where light sources can cast shadows on the particles? I've never seen a game that has shadows on smoke, or light sources lighting particles, or particles with individual light sources. Not to mention the Temporal SSAA or Direction Occlusion.
Ugh, GTA IV's campaign was shit. It was the shittiest shit ever. I had to force myself to finish it and I hated every second of it. Overall plot that was completely forgettable (I've forgotten what it was about), bad acting, bad writing, "NIKO, MY COUSIN! LET'S GO BOWLING!" <- 'nuff said. Plus it was ugly and ran like shit. Best thing about GTAIV was "Four Leaf Clover". GTA V was brilliant by comparison. I couldn't put it down.