I've been using the FX-120i and auto trickler combo for about a year now. As much as I love the FX-120i the auto trickler has fallen out of favor with me. Yes it's great to quickly make a large batch of rounds within 1 kernel or Varget. Where it loses it's shine is when you're doing ladders for load development. You can't punch in the weight you want, you have to manually set the next step in the ladder then set the trickler to the new charge. Half the time it doesn't register the new weight and dispenses the next charge at the lower weight.
Since I seat my bullets while the next charge dispenses the auto trickler doesn't save me tons of time. I still use my RCBS Chargemaster, let it dispense the amount of powder I want, then I use the FX-120i to confirm the weight. Half the time the RCBS is right on the mark, the other half it's slightly over and I just remove kernels manually. Slower for large batches but much less aggravating when loading ladders.
Next time I load 200 rounds I might plug the auto trickler back in. For now it just sits on the shelf. You will see a marked increase in accuracy when using the FX-120i, the auto trickler is a nice convenience tool but adds nothing to the quality of your reloads.
See those 2 older threads of mine if you have doubts on the FX-120i:
https://www.canadiangunnutz.com/forum/showthread.php/1602489-RCBS-Chargemaster-1500-vs-A-amp-D-FX-120i
https://www.canadiangunnutz.com/forum/showthread.php/1477113-The-10-rounds-300-yards-cgn-online-challenge?p=14059821&viewfull=1#post14059821