As most people have already said, it depends on the average ilvl of your raid group. If you're around 575 it's more than enough to clear everything and clearing isn't going to net you a whole lot of upgrades.
I think the way we did it was extend 1 week to kill Siegecrafter once we were close to the kill. Think we went in and it took 2-3 pulls in the new reset to get it down so we had a full reset straight onto Paragons. Again extended since we were close to a kill and came back in to kill it very early into the next reset and spent the rest on Garrosh. Did a clearance run to break it up a bit for everyone and try pick up a few pieces ready for Garrosh. Then extended constantly until it was dead 3 resets later. We raid 10.5 hours per week for comparison.