As mentioned already this is the busiest time in Dubai. You may find your 3 hour layover being eaten into if the plane you come in on uses an outer stand and you have to be bussed to the terminal. That will take at least 30-40 mins. A380s are prone to this as much as the 777s. Dubai is the only place I have had to take a bus from an A380. Its a lot of passengers and takes time. Even if you are in a premium cabin it will take some time to get off although they have C and F class transportation. if you are in economy and sitting at the back you can imagine the time taken to offload.
if you use a stand at the terminal though things will go quick as economy deplanes at the same time as C and F.