karma isnt the BEST support but she is better than soraka and sona right now. i would say she is up there with zilean and janna, but she requires a knowledgeable team and vent/teamspeak etc. to be truly good. while zilean and janna dont require your team to be as knowledgeable or organized
So to throw out some feedback of my own.
I feel that part of the reason people do not notice heals is graphics.
Janna's bubble is nice and big and glowy and the white bar on your health bar is even more obvious. Her Knockup is really graphically visceral. Her ult is..well you KNOW shes using her ult.
In comparison...you hardly notice Soraka casting anything beyond Starfall. A bigger particle effect could have unexpected dividends in how good it feels.
Take wish for example. What if it gave a 3 second buff called "Feels good" and while this buff was up the character sparkled a bit? What if a moon beam shot down over everyones head when you hit wish all glowy? Wouldn't these things just shout SORAKA JUST USED WISH PRAISE HER FOR YOUR LIVING.
And then to compare Infuse and Dazzle. Dazzle has a few problems in that it's a slow moving projectile. These problems make it much more viscerally satisfying then Infuse. A Taric Dazzles, you see it fly, you see the enemy stop, and you know he just CCd. You don't even need to see the swirly stuff above his head.
Now heals in general. Green bar, empty space. You get healed more green.
Shield. Green Bar, Empty space. Green Bar, White bar, Empty space. Heal = the white bar.
So what if instead Heals where blue, and worked the way damage is shown in red.
Green Bar, Empty Space > Wish. Greenbar, LOTS OF BLUE > Full green bar.
Holy **** I just got healed for oodles.
Give some flashier visuals to some of these under appreciated spells and see if it helps.