TheSword
Legend
Pathfinder Core is a great idea - if it can deal with the bloat. That was the main reason we switched to 5e after 10 years - that and the pressure on the DM.Pathfinder APs are good and have some amazing ideas. However I sometimes think each part being written by a different author can make them disjointed. The quality across a series can vary wildly. Usually the first two are awesome and then they go downhill.
They can also be very long, with a lot of padding... dungeons that should probably be a single encounter filled with four or five filler encounters. I almost always ended up combining encounters.
Pathfinders biggest issue was a fear of going over old ground which meant their products and APs became more and more niche as they went on.
To go back to the first point there are some absolute crackers.
What would be amazing is a hybrid system for 5e that added traits and Pathfinder sized feats to the 5e game, but maybe that would be cumbersome. I often like to give a small benefit to players at creation without giving them the power of a 5e feat.