I also use an Eheim. Yes, it is more expensive, but as the saying goes, you get what you pay for.
Last June, I went to Europe for two weeks and came back to fishies that were happy to see us. I hope anyway. Just make sure that you test it's operations days before you leave, to ensure that it delivers the amount of food you want to. A personal observation is to ensure that the flake food is properly prepared/crushed. This way, you ensure that there are no lumps that could potentially block the output and starve your fishes to death.