Both are very situational, but I would say the guardian angel / archangel ability is better overall due to versatility. Holy light takes up space in your deck, and though it may be twice as powerful for a cheaper cost... it's really dead weight if your opponent doesn't take heavy creature control or death/darkness creatures. You'd have to use it on yourself, and in most cases (unless you're going for EM after a miracle) 10 healing for 1 card is a card space that would be better spent on more pillars or more offense. The ability on the other hand has a lot of uses. Rage angels is actually a very good deck if you can get a good balance of angels, rage potions and miracles. And also, in phase one, with my FG deck against Morte, I only won by TUing one of his archangels to keep a dying pegasus i had alive. So it can be used offensively and defensively. Defensively it can eliminate a lot of creature control unless the control is very heavy. Offensively it can be used in combos like rage angels.
