I remember Rooney said one reason they did the hard sparring was so the fight would be the easy part. The hard part was over with. Like I said for some fighters it works others it doesn't.. Just depends on the fighters skillset and mental aspect.
I made a thread after the fight about how th efight was basically a sparring session .... and thats no discredit to Floyd
Yeah, sparring should always be done with some control. If it looks like your oppenant is hurt at all you should back off and let them recover. Don't go for knockdowns/KO's. Your oppenant will know when he gets timed/hurt and learn from that.