i find celpip better then ielts but at the same time there were few things that pissed me off. since all of you are going to be in the same room, there will be alot of disturbances. specially when the guy near you start to type his essay and you are still trying to finish the reading section. when you are finishing your writing and trying to focus, the guy beside you might start his speaking section and there is no way you cannot hear him and loose concentration.
tips for your exam are just try finishing your sections as soon as you can. if you really want to give some section some time, go ahead but be prepared to bear the disturbances in the room. good luck