User blog comment:Willbachbakal/(Champion Concept) Burke, the Apothecary/@comment-80.98.153.26-20121215203516/@comment-1330314-20121215212930

Actually, Soraka's heal heals for 350, equal to the healing from both my Plague and Flu Shot, and she can restore mana as well as grant bonus armor and MR (not to mention globally heal her team). At the start, without runes, items or masteries Burke would be able to heal 7.55 health per hit, which at an attack speed of 0.625 amounts to a bit less than 5 health per second, so if he were to glue himself to a teammate he'd heal them for Soraka's heal in under 15 seconds, which is admittedly significantly better but still not as good as Sona's heal.

You may be right about Burke's passive being too powerful, so I may tweak the scaling a little in the future. I would like to point out, though, that while Burke's passive builds up a lot of healing over time, it's a single-target melee range ability that provides only healing, whereas most other heals affect either multiple targets or grant a bonus effect, and are all ranged.