Bryan is saying it better than I am. I think you're talking about the proper starting ma-ai. To my mind, that is the ideal distance for technique. But, once we start technique, we should still have proper distance compared to uke, and that will vary depending on what we're doing.
I do think that we can make general observations on the distance at which we work. Ellis Amdur called aikido something like "jujitsu at arm's length." In other words, we can say that, generally, aikido works at a more open ma-ai than jujitsu.