I loved the idea of multiple tiers of proficiency when I read about it on the blog, but reading the actual book, it's actually very underwhelming when compared to the the fact that every level, all of your rolls go up by one, no matter whether it's something you ought to be good at or not.
Let's say we have a level 7 rogue who has reached Master level of proficiency in deception, and has a charisma of 20. She's a darn good liar, with a proficiency bonus of her level (7) +2 (Master) +5 (charisma) for a total of +14.
Now let's say we have a level 20 dwarven wizard with a charisma of 8, who is untrained in deception. Her proficiency bonus alone, despite being untrained, is 18, because being untrained still lets you add your entire level -2 to your skill check, and even with the lowest possible charisma in the game, this dwarf is still a better liar than the above rogue.
This also makes the age-old dilemma of 1000 orcs vs one high level fighter even sillier, especially considering that you add your "proficiency" to your AC now, which effectively translates to adding your level to your AC. Even in Pathfinder 1, the fighter would win, but now the fighter's going to win without getting hit at all even if she's only wearing padded armour. Heck, now a high level bard with no spells prepared and wielding a sharpened stick could wade through that many orcs, just because her level gives her such a high bonus to _everything_.
Anywho, for folks who are also finding this getting on their nerves, the fix that I'm planning on running at my home table is just to remove the factor of level from proficiency bonuses, and to increase the difference between levels of proficiency to 2 per shift instead of 1. (Untrained: -2. Trained, 0, Expert, +2, Master, +4, Legendary, +6). I think that the built-in restrictions between what level you can become a master or legend should be enough to ensure that a level 7 character is still going to be better at the things that she's good at than a level 1 character is.
