I purchased the Skerton after trying the Capresso Infinity grinder as compared to my Cuisinart DBM-8 of 4 years. I was surprised how much more consistent the conical grinder was. Since I already had one grinder and the Capresso was more than I wanted to spend, I decided to try the Hario Skerton
That being said, I absolutely enjoy grinding with this unit. The only issue I've had is that my carpel tunnel acts up after grinding for 4+ double-shots daily. There's one step on the grinder which sort of works with espresso. One step more coarse, and shots pour out in 10s, and one more fine chokes the machine. To grind 17g for a double shot using a FC+ roast, it takes about 170-200 turns. It's not hard to turn, just slow to grind.
The grind consistency is very nice compared to other grinders I've tried. I've found it's an ideal grinder setup for my moka pots, the reusable Keurig cups, and Aeropress. For espresso, I'd say it's adequate, but best when used with a pressurized portafilter like on the Saeco machines. For French press, however, it's horrible. Without something stabilizing the inner burr (see the OE mod), it'll never be a good grinder for the French press.
As for the build, the unit housing is most likely made of polypropylene, as it will flex somewhat, but is still very durable like Tupperware. I have no second thoughts about placing it in a backpack or my motorcycle top-box.
I gave it a 6 of 10 for usability because of the silly nut on the top to adjust grinds. It can be difficult to find where you had it set up for moka pot after using it for espresso. If you want to adjust it, you need remove the handle, then turn the nut either CW or CCW. It would have been nice if they stamped which direction to turn the nut to make the grind more coarse or fine too.