T-Rexwrote a review of Tacx Flux Trainer on October 16, 2017
Familiarity: I've used it several times
I was on the fence for a long time about picking up a "smart" trainer and a) would it really benefit my training THAT much over my old fluid trainer, and b) would I actually ride it and justify the expense. I've ridden the Kickr and other products in lab/group class settings and enjoyed well enough but could never quite justify the expense.
I finally pulled the trigger on the Flux and have been very impressed. Of course any trainer is only as good as the software you use to drive it and the Tacx stuff is pretty decent. I've been using with Velo Reality and have been really happy with how it reacts to the video and GPS track of the rides I've paired it with.
I find there is a little dead spot in the gradient difficulty between 8-10% simulated, although this is likely software rather than the trainer. Overall the "road feel" is very genuine. My simulated speed and power output are very consistent with road data in the same gears at the same cadence and speed. The ability to run virtual training software is fantastic and makes boring sessions a bit more interesting and appealing.
If you're on the fence about the Flux, I'd recommend picking it up. It's every bit as good as the more expensive competitors and $400, or more, cheaper. Very happy.