Last time I checked window capture from my capture card's software the OBS window would still drop frames every few moments while the avermedia tv window was staying smooth, this was back on the 0.10 build.
Since trying out 0.11 the frame drops in OBS have been less but not completely gone, but this could also be due to windows 10 being updated to the point where it's more or less final build now, or at least it's one big update away from being the launch version at the end of this month.
Overall though OBS multi on windows is producing better looking video then the old OBS did on the same old core2duo i'm stuck using and i'm really happy about that.