Health Regen Runes; Are they worth it?

Hello, All! Looking in to runes I need to buy, and I'm not sure if these need to be on the list. While many champions (Such as Darius and Heimer) laugh at flat health regen runes, there are a few champions that make me wonder; Namely, Soraka. With the rejuvenation bead standard of 3.6 gold per 1% increase in health regen, Having Quints + Seals is worth roughly 1892 gold at level 1, scaling down to 430 gold at level 18. However, given that it is an extra (roughly) 2.6 health regen a second, is it really worth it? As with so many champions, I have a hard time justifying the use of these runes over their alternatives; I.E. On Mundo, I much prefer either Scaling CDR or MPEN. On Soraka, It might be better to run flat AP for the health back on Q, as well as harass and better heals. This is largely in part because the additional health regen is not part of your base (unlike health regen gained on level), causing them to become increasingly inefficient as you itemize as well; For instance, Just throwing on a spirit visage halves their effectiveness. As such, Are there any champions you would use these on (Assuming you could use any rune you wanted to), and why?

On a second note, Do you think these would be better if they were re-balanced as base health regen?

Thank you for your time & thoughts all! =).

Also, for anyone curious, without interference of masteries or items: Average health regen of all champs at level 1 = 7, At 18 = 18.136, Quints & Seals give a combined total of 13.14 Health regen/second, Making them worth ~720 gold at level 1 and ~270 gold at 18. Gold efficiency is inversely proportional to %Base health regen modifiers (Doubling base health regen halves the gold value).