I personally love the idea of freemium and the potential it has, but he's right to say that most of the time it's done poorly.
If I had it my way, I would release all my iOS/Android games as completely free, start to finish. You would be able to download the game and play through every level on every initial difficulty level as well as alternate modes, and earn points and unlockables and such, BUT... the only way to use points earned to purchase unlockables would be to buy the "full" version, or activate your game via in-app purchase. The price would be fairly low, and you'll immediately have access to everything you would have had if you had purchased it from the start. That stuff would simply be game-extending and hardcore extras, such as extra characters, super tough difficulties, challenge levels, maybe level editor, and cheats.
See, that sort of system means you can play through the whole game with no problem, unlock achievements and stuff all the same, but the only thing you don't get is the many cool features you unlock for purchase and the points you earn to buy those unlockables are stored away until you actually purchase the game.