This build confuses your protoss opponent by proxying your first barracks.It also allows you 10-15 seconds to kill probes before units come out with your first reaper. The protoss will already feel under pressure and confused. Your follow up cyclones will have vision with the floating barracks and you will end the game in a timely fashion. 5 minutes or so on average
This is a 1 off build that is good to keep in your arsenal. Throw this in every once in a while and get some free wins.