Main problem was and if it will continues so, always will be confirmation of transactions. If you are going to make transaction of higher than 1 bitcoin with normal fee, than sometimes there is problem and you have to wait 1 week or in worst situation delete transaction in order to make it forgotten for networks. Another problem is that there is no chanse of returning sented bitcoin if you sent it in wrong place. All other thing are perfect.
The best way for try to fill your transaction fees with more money. Such the system was seeing your transaction be un-prioritized transaction. Spam can happen anytime and make your fees a higher than the first number was appearing.
But even if that will back to the previous place but it will take a long time and so boring.