I just did the i6 firmware update. got 14 channels though I don't really need more channels, but the Timers, and battery alarms are nice new features though. More mixes would have been nice, but it still only has 3 on X or upgraded i6.
(Note:- you can sort of use elevon mode as an extra mix)
If you have neither i6 nor x and are buying one, buy the X to save you some trouble.
If you already have the i6, buy the data cable and do the firmware upgrade to get basically the same thing as i6x