FireLance
Legend
IMO, the harm spell was more unbalanced than the heal spell. Interesting lack of symmetry there, I suppose - I guess conceptually, it's difference between more chances to win and a near-automatic win. The former holds more uncertainty and tension than the latter.Healing scales with base hit points. That's not as problematic as some of the other ones, but I do have some issues with it. If take it to the extreme, you have an effect that simply restores someone to full health, that can be quite unbalancing (the Heal spell used to do this in 2e and 3e, but was revised for 3.5). The converse is the old Harm spell, which was also rather unbalancing.
I'm also not a big fan of math. Scaling healing with hp presumably forces one to calculate fractions if you're not healing all of your damage at once (honestly I don't know 4e mechanics to that level of detail so I don't know if that's the case but it seems like it would be). Sometimes that's necessary, but I'd like that kept to a minimum.
The last thing is that I think it's important that magical healing reflect the power of the caster, not the target.
I don't see at as being a huge conceptual dealbreaker, but I'm fine with CLW being 1d8+CL and so on.
Anyway the 4e system is that the standard unit of healing is 25% of your maximum hit points. This is calculated in advance, so there is less need to do the math at the table. Characters who are particularly good at healing are often able to heal extra hit points on top of that. For example, a low-level cleric might allow you to heal an additional 1d6 hit points, while a high-level one might allow you to heal 6d6 additional hit points. So, the number of hit points restored are a function of both the power of the recepient and the power of the healer.
That said, although 4e uses 25% of maximum hit points, it isn't necessary to stick to that percentage, especially if you think that hit point recovery is too fast in 4e.