Honestly, Grievous Wounds affecting her heals impacted me the most during laning phase. I had to think about when to trade.
Outside of the lane phase, eventually that ADC and/or APC was gonna crit 800 every 1 second while i'm still trying to heal for 200 every 1.5 sec. Even if I went pure AP, i was a walking stick with no leverage over any fight that happened (like supports are desired for).
So what's the real problem?? Pure AP got too expensive, and in averagely shorter games your carries don't have as much time to outscale that 200 heal now boosted by 10%, armor, and MR.
But let's chalk it up to a complete design failure which is OK by me. I played her 1400 times, I got my fun with her, and seeing as how she was already reworked, didn't expect this one to last either. I'm pretty damn sure Sona is next. These kinds of champions just set themselves up to never be seen competitively.