I'm afraid I can't give you a definitive response on that. You know how it is, it depends on your audience, their expectations and how far each topic strays from the other. It is possible to keep everything tied together on one channel and if the content is similar I would personally push for that approach. You see gamers do this a lot, where they cover different games under different playlists. You can have different styles of videos in different playlists. Personally I do a trip to Cozumel every year that is supposed to stand as our winter-time vlog between fishing seasons. Totally out of left-field for our audience, who often looks for information on Texas fishing. I get weird results from this; our audience tends to abandon us during this series... but it does really well in Search all year long. What typically happens though is that they understand it is a one-off series, and that the regular content will return. When it does we get a pretty nice boost as that audience now has a return to content that they had not seen in a while. Ideally I would like this to be semi-annual and something that covers journeys to different locales (my wife absolutely fell in love with Cozumel, I can't get her to go anywhere else lol).