I've just been trying to find something else. The last three spools of 3.3lb 0.15 Supplex FC I've had have measured 0.154, 0.145 and 0.14. That's a range by their measure from 2.87lb to 3.48lb. Given that a skilled angler can land pretty much anything with whatever line he/she is using (snags aside) I take the view that consistency is possibly the most important property of line. How else are they going to get used to the limitations of the tackle? I like the stuff in every other respect. It's easy to tie, not too stiff and strength to diameter wise it fairs well. Maybe that spread is as good as we can expect but it seems a little wide to me. Just had some 0.152 Sakuma delivered which measures 0.152 but it's a bit wiry for my liking and 0.152 is the lowest they do and there's no saying the next lot will measure the same.
On the other hand I have two spools of 4.4lb 0.17 Supplex FC which measure 0.17 and 0.168 which I'd say is pretty good.