To complete the circle- I got one (thanks to a member here) and I've put about 500 miles on it now, so here's my quick summary: I didn't find it difficult to set up- the handlebar end cable pull works fine, and I have not had any events like it spontaneously being pulled from 1st to 2nd or 2nd to 3rd, even honking out the saddle up some of North Yorkshires finest gradients- it just hasn't done that. The cable run is via a pulley on the top tube. I didn't find the adjustment very finicky to get right.
I've taken it apart, cleaned and regreased it, and nothing internal looks awry- the only comment I can make is that, having looked at the mechanism whereby the sliding dog in the axle (that is actuated by the cable pull) has to move between the stops that engage the planet cogs for 1st and 2nd, I'm not surprised that there is some chipping on one corner of the dog. It's likely caused by shifting up under pressure, or from 3rd straight through to 1st without pausing in 2nd- the leading edge corner gets mashed by navigating from one set of quickly rotating stops to the other, but it doesn't affect the change. The lash is caused by the space between the adjacent stops for the particular set of planet cogs that the dog can move between. It takes a little getting used to, but its not excessive.
False neutrals do exist, but if the gear lever is snapped in position, the indicator chain adjusted correctly, and the axle sliding dog isn't smaller than it should be, then you won't find them unless you want to.
I've found in common with others, that 1st gear is harder work to push than the bald gear inches would indicate it should be if you were on the equivalent fixed gear-inch, but its agreeable enough to get you up hills. The strip and re-lube helped ease that "feature" but hasn't taken it away.
All in all, I like it. (It's also fun to watch the eyeballs from those with 22 gears avaialble as I mash up hills with gritted teeth on a 70's frame with sprint bars, hub gear, 1/8 chain and my non-aero brake cables and bar-end changer looping elegantly around the handlebar area)
All good fun. It's now my go-to fixed.