The DXe is an interesting concept, but I would never want to pull my phone out to change any settings.
I have a DX9, have had it now for about 3 years. Boy, what a radio! One of the gimbal springs came off mid-flight giving me quite the scare, but I wouldn't disregard this radio for that alone, as I haven't heard of anyone else having this problem. It's voice alerts are absolutely fantastic- you can create pre-flight checklists, read out telemetry, and say pretty much any RC related phrase whenever you need it to. I just use it for timers, and to speak the flight modes for my T-Copter. The SD card is also something great, as it lets you update firmware, add custom sound effects, transfer and back up model files (of which, you can just about have an infinite amount of), etc. Unlike the 6i, its screen is a higher resolution and is backlit. The extra pixels let it show graphs and displays of channel activity, and mixing logic. Most of this stuff is included with some of the newer radios, but when I bought it it was better than the 6i, and reportedly even the 18 even though it has 2x the channels. I guess just because the features are worth more to most people.
I would start with the CHEAPEST radio that you think won't immediately limit your flying experience. That way, you feel much better buying any other brand, model or type of radio that you like better later on.