The Randy needle has a finer thread, finer adjustment. Useful in some applications. The click click OS needle works well in the LA46. An engine with a wide spread of usable tune. Using it means no need to drill the case. Not so easy to get the holes true and exactly lined up. Holes which then have to match venturi holes. Folks asking these questions benefit from the easy fit of an OS stock needle. They are not the most experienced. The comparatively docile LA46 does fine using the stock FP clicker. Any contest I've attended, since these engines were discovered, is flooded with LA46s using OS needles.