So...Let me give you my two cents, which, admittedly, is worth that or maybe less.
The brands of transmitters are Mac vs. PC, Ford vs. Chevy, BMW vs. Mercedes, iOS vs. Android - you get the picture. Each transmitter has its pluses and minuses, and in a lot of respects, you get what you pay for. Now, when I say that, you may get some features you want, but at the lack of others - or, you may get a bunch of features, but no support other than a YouTube video, or you may not get a warranty, or you may get cheaper parts (I remember looking at a cheaper Taranis radio when I was first looking at transmitters, and the sticks felt REALLY mushy, with no ability to adjust it - it was also $50 cheaper than the other radios that I was looking at, so that savings showed in the controls).
Another example to watch out for is how many models they can store. I currently have 18 models in my storage - 3 different quads of varying sizes, 2 USB computer connections, a Sea Duck, trainer settings for the Apprentice, an FT Mustang, and multiple different BNF planes that I've bought. With the DX6i, it's got a limitation of 10 models. That, for me, was a pretty big reason not to go with it and step up to a DX6, when I first got into the hobby - I KNEW I was going to have a fleet of aircraft to work with. Is it a problem for you? Maybe, maybe not - that's up to you to make that call.
There are other issues to consider as well with the radios - what TYPES of planes are you going to fly? Are you planning on flying a warbird with retractable landing gear, flaps, and bomb bay door releases? If so, you'll need a channel for each of those things, in addition to your standard throttle, rudder, elevator, and ailerons. If you're going to fly big gliders, you may need even more channels, for things like airbrakes, tow release, and telemetry. That's material to be aware of REGARDLESS of brand.
Now, if you are planning to buy bind n' fly (BNF) planes, know that a good portion of them are using DSMX. This means you need either a Spektrum radio or one that's compatible with DSMX, OR you'll need to change out the receiver to use a different receiver compatible with your transmitter. There may also be some radios out there that say they'll support DSMX, but they have an asterisk on it - you'll need an additional module that attaches to the radio to offer that functionality, and will be an additional cost.
The last thing I would bring up is support. I fly Spektrum because at my field, most of the people who are there fly Spektrum. It's somewhat of a "jump on the bandwagon" feel, but it's not for the reasons you think - I did it because if I have a problem with setup or configuration, odds are, someone at my field has run into it and can help me troubleshoot my settings. That may vary depending on where you're at - if you're flying in say, South Indiana, you may find that the guys there fly Futaba. Or you may fly down in Florida and you find the guys there all use Graupner. I mention all of this because if you decide to buy a radio that nobody's really heard of, you may be stuck getting support from a YouTube video, or worse, from a manual that was written by a programmer into Chinese, then translated from Chinese to English by someone for whom English is a second language. And of course, if something breaks and the manufacturer is in China, you may have to send it back to them on your dime - which, with current tariffs and shipping scrutiny, could end up being as much or more than the transmitter.
So...What do I think you should get out of those choices? I like the DX6i - it's easy to program, it has DSMX, it's a solid radio that a LOT of people have dealt with, and it'll be relatively inexpensive, lasting you for several years. Disadvantages are that it's limited to 10 models in memory vs. the "virtually unlimited" model memory on a DXe, but the DXe is something of a pain to get programmed since you have to use a programming cable or optional Bluetooth programming module. Also, the DXe does not play well with quadcopters, so I am hesitant to recommend it for that very reason.
Hope this helps!