I built up two bikes with them in and both are suffering from what I would call ‘lever stiction’
The lever arm on these seem to be made of cheese and has worn down somewhat. The interface between the lever and ball bearing at the top isn’t great meaning after a while its harder to press the lever than it should. It appears to be wearing faster than my 6 year old KS i950 (which is still perfect with no maintenance apart from a cable change two years ago)
Also the remote lever itself doesn’t seem to have enough cable pull. I found to get the seat working up and down nice and fast, then you need very precise cable tension..something you don’t need on others.
Leaving the cable slightly too slack results in a very slow to operate seatpost. Too tight and it doesn’t lock (or can creep down slowly)
For the money, its a great bit of kit though.