Scenarios during which preserverence is better than indicated by op:

Champion has other sources of regen, such as garen.
When using a potion, in order to heal more.
When being healed by soraka or another healer.
When self-healing with abilities such as Yi's meditate.
Abilities such as vlad/warwick/morgana's lifesteal.
Lifesteal in general.

There are more situations that I can't think of at the moment. I'm also unsure if preserverence helps lifesteal or other abilities. I'm not sure if preserverence is better than good hands, but I think we need to weigh the situation with full information.

You're sure it doesn't affect heals? The tooltip can be interpreted ambiguously. Like vlad's pool ability (it should only stop him from being targeted, but it actually makes him immune to all sorts of AoE abilities and ultimates).

Also, golem buff will be better with it.

I doubt it affects heals or lifesteal. And good hands is probably better. This thread was eye-opening for me, as well. I never considered the op's math.

Lets face it, most of the low level masteries are just plain sad...with a few exceptions. The real reason to get any low level mastery is to unlock the ones that are actually worth a sack of monkey ****.

I will concede that 6sec can feel like an eternity, and on occasion, (though rare) could actually be the difference between winning or losing a fight. However, as has already been pointed out, some characters benift from regen more than others; so I wound't say perseverence is totally useless. It's defintly low on the totem pole for most champs though.

Personally i would much raher see it give some fomr of a flat gain, instead of a % gain. It would make it much more useful in the early phase of the game when regen is needed most.

It says % increase. I'm not sure how you could interpret that as per second or per 5. It's %. The math is correct.

This is exactly the reason I don't take Perseverance anymore. It's an incredibly minute jump, most of the time less than 1 hp/mp5, whereas the 10% death timer reduction can be a big deal late game when your team just lost a bunch of people in a team fight.