So concave top discs are what we call puddle tops now? Puddle tops used to be discs that had a little divot in the middle above the nipple like 8X KC Rocs. Using the old terminology, the Yeti isn't a puddle top. It more like a whole pond.
Language evolves, so no biggie.
Thank you for pointing that out. Sounds like puddle tops are unintentional with minor levels of concavity, as opposed to the Yeti and Berg which were purposefully designed with a more pronounced concave top.