Medias? Or is 'media', like 'stadia', derived from 'medium' and already plural? Hmm.
On G+, I feel I should curate my uploads a little more, put them into interlinked sets which I can write a little about, share my musings with the wonderful community there. On 500px, meanwhile, almost the opposite is true - in the homepage there, my photos' captions aren't shown at all, so I feel I should only post those images that can speak for themselves - there, photos can't require an artsy caption to pick out the story I'm trying to convey, because most of the audience won't read the caption and therefore won't get the full story.
In, future, then, I will be distributing three parallel streams of photos... But they won't be identical. And maybe, having devised approaches tailored to the specifics of G+ and 500px, I'll take another look at Flickr some time soon, and tailor a stream for that medium, too.