It's funny how wide the guess range is that the client thinks you will need before it gets included in a certain block. In some cases it gives people false hope as they purely focus on getting their transaction confirmed within an x amount of blocks as suggested by the client. It all depends on whether the pools find your transaction worthy enough to be picked up. But it's not always the pools to be blamed for not including certain transactions in their block. I still find it quite shocking that some people include fees that are far lower in number than 0.0001BTC. They either have no clue of how the current network situation is, or they try to save out a few thousand Satoshi's by adding lower fees. Not sure which of the two reasons is worse.