Years ago, I went from the simple guide to the Gransfors manual sharpener. It provided consistent sharpening of the teeth, but was kind of fiddly and every time I would use it, I had to remind myself how it worked and relearn it, as I use the saw at irregular intervals. On a whim, I bought the Stihl 2-in-1 sharpener, even though it really bugged me that it was so expensive. It's amazing how much faster my saw cuts after a bout of sharpening with this thing. There's still a moment of head scratching as to how to line it up when I first pull it out, but then zip-zop, sharp chain. I rarely filed the depth gauges and the 2-in-1 files them each time you sharpen, so maybe that's the difference, or maybe it's just more precise to line it up than a plain gauge. Whatever it is about it, it works, and I've made the money back by resharpening chains I thought were so bad I needed to take them in to the saw shop. It won't rehab a chain that's bitten the dirt or hit a nail, though. For that, I take them to the shop, but after seeing this video, maybe I'll invest in the HF grinder-sharpener.
I really like how he figures out a way to remove confounding factors, like using a bundle of 4X4s to make the task more consistent or hanging a weight on the bar to eliminate human factors. One thing he didn't appear to do, is to use a vise with each tool. At least he didn't in showing them in action. A vise really makes a difference for me.