Bob Gardner wrote:

I think the whole WAAS thing is in flux. The AIM gets wordier and more
difficult to interpret with each change to its discussion of GPS. IMHO,
until there are a whole lot of WAAS capable boxes flying in the system we
will be flailing about in the dark.

You're right on. And, in an effort to sell LPV (WAAS) minimums, the friendlies
"tweaked" the VNAV missed approach criteria so that VNAV minimums will increase,
all to make WAAS look better.