I am current trying out a power recharge system myself, its the Acheron system found on the house rules board.
I will say that I think missed encounter and daily powers are the reason that on occasion solo fights can take so long.
In 3rd edition, the fighters were a source of constant, strong, dependable damage. Now towards higher levels we all know that wizards and clerics start overriding the fighters. Save or dies and the like could end the fight in a round or two. BUT....if those effects failed, the party had a couple of options to compensate:
1) The spellcasters blow more power. The party might have to rest earlier or face other issues. But at least in that fight, they can take out the monster in a reasonable time.
2) Rely on the fighters for damage. The spellcasters back off, and let the fighter finish the job. The fighter certainly isn't as efficient at high levels at taking out monsters, but he can still get the job done in a reasonable timeframe.
In 4e, especially towards higher levels, the party's "power" is stored in their encounter and daily powers. Whether its simply raw damage or effects that help the party kill quicker, their powers are what get it done. If those effects miss, the party loses out on a lot of power. Even a missed daily does FAR less than it does when it hits. And unlike the 3.5 fighter, they can't get that back. They resort to at-wills, which deal a lot less damage overall.
So I am definitely in favor of some way for a party to get powers back, whether its a recharge system like I'm trying, or some of this "miss but don't miss" mechanics present here. I do agree that there should be some compensating mechanic for the problem I mentioned above.