I have ET and I am not a big fan of it. I signed up back in the day when they gave cash bonuses. I find the fees and vigorish too high for a small-time trader, and sometimes they take their sweet time with my market orders.

Which one you pick will probably depend more on the frequency and type of trades you make, and not so much the miles offered. Some brokers will be thousands of dollars cheaper for you in the long run if you are an active trader; others will give you super-low commissions if you only make a couple of trades a month. Don't get locked into a bad brokerage for a couple hundred bucks worth of miles. The ones that don't offer miles usually have some other teaser, such as free trades, cash bonus, etc.