I see quite a few posts on this forum about various waxes and sealants lasting 6-12 months.
I have used most of the products mentioned (Collinite, Duragloss), and I usually 2-4 months of strong protection under fairly favorable weather conditions.
One common statement I see is that there is visible beading...so there must still be protection. However, most clean paint will show some amount of beading even when there is no protection present.
To me, if the paint is well-protected, I would expect to see strong sheeting and beading during the wash process. I should see the water being repelled. The paint should also be easy to wash, and dirt should not be sticking to it.
Here is what the Opti-Coat 2.0 looked like after 10 months of service on my car - this is the standard that I generally look for:https://www.youtube.com/watch?v=duM7HJg_x0I&feature=youtu.be
So, this brings me to the question - what do you consider to be a sign of active "protection" on your paint?