Regardless of what options you are buying, the deeper in the money the better. There are a couple of reasons why this is the case. One simple reason why is that the time value attached to each option is lower for deeper in the money options. Another reason why is that it provides extra cover intrinsic value wise if the trade does not do what was planned.
Analysis of the recent trades at Trading Futures ETF Options blog has shown that one of the reasons for the sale of the option is due to its time value decay. Minimizing it by buying deeper in the money calls seems to be an appropriate action. Trades might be able to last longer and become more profitable if the time value did not decrease at such a high rate.