I dont know why everyone is so stuck in this search for the holy grail. With the amount of time and money people invest in searching for the right EA they could learn enough to be successful traders of their own. EAs are programs that are reading indicators the same as an individual. The difference is because it is a computer program, it is only good as long as the conditions it was programmed for are good. The moment the market makes a huge change, and it always does, the EA begins to fail. The difference? If you are manually trading you can make corrections, if you are EA trading you might come back to an account that has been stopped out.
Just make sure you find an EA that follows your trading strategy and find ways to minimize your risk. An EA traded on a demo account only, in my opinion is garbage. Why if it is such a successful EA, is the developer afraid to commit REAL funds to the EA? Why should you trust an EA that the person who created it doesn't even trust? Why should you commit funds to an EA that the programmer didn't even commit funds to? And an EA that has too much marketing behind it, likely is a hype making machine rather than a money making machine. Use caution and good sense when choosing the EA to use and dont allow excitement or greed to cloud your good judgement.