Well, I'm an iPad user, and I have to say that rowspaxe has a point. File management jobs that one wouldn't even think about in OS X one must spend a few brain cycles trying to figure out. Things like, "How am I going to move this movie onto an SD card so I can give it to an associate? I'll move it to iCloud, and...no, I'm on cellular, it'll take forever. I'll get that little Leef thingy that...no, it's in the other bag. I'll dock my iPhone with my Macbook, figure out the protocol for getting at files, and..." By now, on any other platform you'd have moved the file and you'd be on about your business.
Look, I love Apple stuff, own a bunch of it and I'll probably buy the iPad Pro with all the fixin's. Somewhere along the line Apple is going to need to figure out how to legitimately manage data files without breaking their sandbox architecture, and the "open in..." dialog isn't the final solution to that problem.