This is really a "Ford vs Chevy", "Apple vs. Android" argument. Both have their pros, both have their cons. I went Spektrum over Frsky for the following reasons:
- All of the stuff I wanted to fly when I was starting was Bind N' Fly, so I didn't have to change out receivers
- Almost everyone flying at my field was on Spektrum, so if I had a problem with setup, I could get help
- While the Taranis radio I was looking at was cheaper than Spektrum, the cost to replace the receiver in my first quad, PLUS upgrade the gimbals to Hall gimbals put it a little more expensive than the Spektrum DX6. Plus, I would have to replace the gimbals myself, which instantly voided the warranty; if I screwed it up, that was on me. I was new to soldering at the time, didn't want to take that risk.
- Ergonomically, the DX6 felt better in my hands than the Taranis I was looking at. This is a personal thing, but it was a factor for me when I chose the Spektrum over the FrSky.
As someone else said, it's really buying the radio that best fits YOUR needs.