You should use dxgi in all scenarios. Gdi is off the table. Wgc causes stutters in games with fps drops for me. I use dxgi with 4x frame gen and performance mode (for videos). With new update i have got really good smooth picture with not much artifacts at all (for videos). If you use low base fps with 4x in games it has artifacts though. I am kind of shocked you said there are lot of artifacts. For games i think you should use at least 40 fps to get the least artifacts (60 recommended for great experience)
#Which Capture API should i use?
real steppe
eager oasis
i use x3 with 40 fps performance mode and i couldnt see any artifact , also i tried x4 performance 37 base fps and still good