In my experience playing SW Saga, I see players hording their action points carefully, spending them only to stave off death. Nobody wants to see their character potentially crippled by running out of APs before a battle when they might really be needed. The irony is that special "battle" never seems to arrive so the players just horde them. I feel the same way as a player. I don't want to spend them because what if I really need them and I have used them all? That's just player psychology.
I have found that the opposite is true in Spycraft 2.0 games, for example. Since APs are per session, PCs feel much better about spending them and trying to perform cool stunts. The game is much more fun and active.
It goes right back to the heart of the same design issues that WotC talked about regarding per day Vancian spells. I just don't see how WotC can reconcile moving to an encounter system everywhere except in action points. Hording spells to avoid pulling out a crossbow is obnoxious and unfun so they changed it. So why use similarly bad mechanics for actions points?
I'll offer up another point that says per level is a bad idea, it requires players to have a DM who is good about allowing you to level up either right before you run out, or shortly after you runout of action points. I play with a DM who likes to not even track XP, he just says when he feels like the PCs should level up. Normally, I don't mind this.
But with a level based resource it really exacerbates the hording mentality. When you don't know when you can refresh a level based resource, you will only spend it in a life or death situation. It is seriously affecting my enjoyment of the game. Unfortunately, the GM believes that if WotC put it in the book it as if the word of god has spoken. To house rule APs to be more user friendly is just crazy munchkin talk as far as he is concerned.
And thats another issue. WotC's words have immense influence on how people play, so its important to come up with mechanics that are fun, but also serve as a buffer to protect players against bad GM judgement, and also gives GMs tools against abusive players. And level based replenishment just causes all sorts of issues all over the board. Please drop it.
