This is already how I'm planning my advancement in my home path game, instead of leveling you gain advancements towards the next level after 4 of them you "level up" to the next level.

The Advancements they can take are: BaB/HP, Skill Points, Saves, and Features. Also in between 2 levels (1-2, 3-4, 5-6, ect) you may take a Feat as a 5th required Advancement, you can take it at either level but you can't become a 3rd level without taking it.

So I like your system, very much so.