I purchased a spool of the 30 denier GSP thread and am very impressed. Once you get used to the slipperiness of GSP, it is as thin and strong as advertised and virtually disappears on the hook. Extremely easy to split to insert dubbing, CDC, deer hair, etc., for a split thread technique, but is thin enough that I think you could form a dubbing loop with it, if you prefer, and never notice any difference in bulk. Needs to be trimmed with a razor blade.
Anybody have other thoughts on it, good or bad?

Joe