i ran the KMW ones all summer, and they are no more work than clip style shocks, some of the things i liked about them;
- i dont have to waste space in my pit box with extra clips,
- i dont have to worry about clips coming off in a crash in the middle of a race, (i've had that happen, come off the track after a race and the back end is dragging)
- if i break a shock shaft, or shock end, i dont have to worry about loosing the spring perch and all the clips, and having to go searching for them on the track, (had this happen too, never did find all the clips)
- i personally find it alot easier and more precise to change my ride height with threaded as opposed to clips, with the clips it always took me three or 4 combinations to get it where i want, with threaded its just a turn of the nut and its exactly where i want, IMO ride height is one of the most important adustments, and clips are just not precise enoguh for my taste
if the threads do get dirt in them, you can either spray them out with brake cleaner, or use a tooth brush and it comes right out, they dont have to be absolutly spotless, as long as the big chunks are gone, the nut still moves fine,