A typical M10 hex nut might weigh around the same as one of these titanium acorn nuts.
A m10 acorn nut might weigh around .75oz or .35oz more than a titanium one. If you have 7 head nuts, that might save you around 2.5 oz or almost half the weight.
If you currently have just standard hex nuts, these will make your quad look better, wont add or lose any weight,  and they don't rust like steel.