There is less volume in the ES then there use to be so that alone makes it harder, at some point you don't even think about who is taking other side, I just look at trading as I am competing against myself. But really, it comes down to your trading plan and backtesting far back enough to know what to expect and help answer questions that will come up. First 30 minutes, orders are gobbled up, then 2nd half hour less so, and after that even less. I prefer to back test than actually trade now, really wish I was when I first started, then I would not have lost so much money and years. Every signal you have you should have stats and those stats broken down in contract months, then months, weeks, days. It is like those who are really into fantasy football, if ya don't know the stats, you most likely not going to have a good team.
The reward comes from how much work you done before trading, sim trading, getting yourself into know what to do before the problem arises.