And more importantly, no dice are involved. It's quite possible to CLW for 2. Lesser Vigor always heals 11. Since combat healing is mostly a waste of time better spent winning the fight, the time doesn't matter.
With DR/5 Magic or Silver, your DR can be penetrated by a Magic weapon or a regular Silvered weapon.
With DR/5 Magic and Silver, your DR can only be penetrated by a Magic Silvered weapon, and that's it.
So when you're fighting a rakshasa (DR 15/Good and Piercing), remember to pack your holy crossbow. If you're up against a lich (DR 15/Bludgeoning and Magic), you'd better have a +1 or better Blunt Object of Bluntness.
If you decide to fight a Solar (DR 15/Epic and Evil), you'd better be packing some serious heat. The Sword of Kas, perhaps?
Most of them. Seriously. Out of the PHB, only the fighter and the ranger lack builds with charisma at least as a secondary. PHB 2 is a bit less generous, but gives you Bard and Barbarian, while PHB 3 adds Ardent and Battlemind. Out of other sources, we get Assassin and Vampire. Charisma is one of the easiest stats to build a hybrid around, right up there with Wisdom.