Legend = Unlimited Extension - Jondal'ar Silvertongue

I feel like losing 2/life of a much less effective Meta-Magic isn't quite a trade-off for the power that unlimited Extension gives.
I DO think that Legend needs a change, I think this is a little too much power. Compare it to Wizards Battlemage. You are locked into a playstyle when you pick Battlemage, you lose self-protection with Ward Self, you lose mid-close combat potential by losing spellballs. You are locked into using /refresh spells to combat your counters. And Wizards still have to cast everything within threat range of other casters, which opens up a lot of counter-play.

Bards have a ton of CC and movement based verbals. A significant portion of these are per life, which is HUGE when you consider the consistency of their power in a game. Adding that ALL their verbals are also extended gives a large edge to them since they can now "stop" a team around 50 feet instead of 20.
Consider that this can also be coupled with Dervish.
Bards are very strong in games where playing defensive is the key, since it is so difficult to get past the initial CC they bring. I think this might push that over the edge.

Bards also remove a lot of their natural counter-play by being able to cast everything outside of 20. Wizards can normally shut them out with Break Concentration, or with other verbals or trade verbals with them. This lets the Bard freely CC them with Awe or similar outside of 20 and then force them into a situation where they can't cast at the Bard anymore. Aside from the Wizard taking Extension and Suppress Aura (/refresh) there isn't anything a Battlemage could do to counter this play-style. Druids only really have the option of Lycanthropy to stop most of their CC but they still succumb to Terror, their Golem is the exception to this. Healers have a lot of Release, but the Bard has a few options to consistently CC the Healer with and prevent them from doing their job or countering this play-style. Bard vs Bard is a trading match-up that generally favors the one who can cast faster, or switch on Song of Interference and run the other one down.
Few melee classes have good options against verbals, and less against Extended ones. Monk doesn't have to care, but the Bard is still allowed S/B and armor with this, so they likely still win. Barbarians can get in when the Bard doesn't have Terror or Shoves, but otherwise have few options. P/AP are notable here with superior armor and Immunity to Command, with Paladin being the one that shuts out the class the most. But Paladins are rare enough that this won't matter very much. Archers have a decent chance against this but shields will counter half their arrows, Mend and Song of Deflection + Release will counter most everything they shoot.

There isn't much a downside to losing only Swift. Swift is largely lackluster for Bards, they have mostly verbals and the rest of their utility have 1 line incants (except SoV).

I think a more appropriate limitation would be to add either:
1 Disallow the Bard from purchasing any Meta-Magic other than Extension. I don't think this choice balances it out well enough.
2 Restrict the Bard from purchasing enchantments. This makes them *more* vulnerable to projectiles and casters. Shields counter this.
3 Restrict the Bard from purchasing equipment past level 1. This option makes them the most vulnerable to melee classes.

My other alternative which is one I have been toying with for a while would be to reword Extension to Charge x3 in addition to its normal frequency (no doubling). This forces some amount of resources and time to be used to utilize it. And forces the Bard to make better choices for when to use the Extensions, and it still gives them the potential for unlimited uses per life.