Not sure , if my reply would help you in any sense, but I am going to try .
I was working on a plugin once, which captured the Jive Profile Image and saved the Image on the Server at a Particular Location in a directory . Later, that Image was accessible via URL.
I believe, it doesnt matter if the Platform is Hosted or OnCloud , as long as You have the Permission to Insall plugin and Restart the Application Server.
Regarding Performance, Beyond a particular size, I believe the impact would be there , but the impact is subjective.