Well, I'm not from NA server (I play at Brazilian server, here is my kinda crappy lolking atm: http://www.lolking.net/summoner/br/2388439), but I'm a true Soraka fan.
It was my first champion to master and i had more than 200 games with her during season 3 when I started playing.
As a main support I feel (and would like to be proven wrong if anyone would)that in order to help my team more it's better to pick a different support than Soraka (that lacks hard cc and escape, which I feel makes my bot lane vulnerable to the enemy's jungler ganks or mid laner's roams). I feel support Raka is a very situational pick for me...
However, I always enjoyed playing Soraka and when I started playing her like a tanky mid laner I felt I could have a supportive role in my team and do more for them in that way than picking support Raka (imo).
In my opinion, again, I do not feel her mid lane playstyle was unhealthy at all. She was (before being gutted in patch 4.8) a tank support oriented mid laner that didn't deal burst damage (if you were solo killed by a Soraka in mid, well, my condolences you are not that much of a mid laner) that had a different playstyle that people are not used to.
I think the same goes for Lulu mid, she's a support oriented mid laner and kind of needs someone else dealing the damage (which is happening more with top lane carries being more viable nowadays I guess).
I didn't feel that Soraka's q was such a problem (if anything it would put her in risk of the enemy's jungler gank by pushing the lane to far, specially in top lane, such a long lane for a no escape goat lady) due to her range being fairly surpassed by the aa and spells of many mage mid laners. Besides that, she could be easily bursted by an assassin such as Fizz as her w does not provide magic resist and has a long cd (bait Raka into using w, kill Raka aftewards).
I think the reason she got nerfed to the ground in this patch was due to the fact that people did not get her mid lane playstyle or her role as a tank support oriented mid laner and because she is a anti-hyper carry mid laner. People have said that Riot did something innovative by trying to create a support that would force a passive lane, but shut down Soraka solo lane because she'd slow the game's pace (btw, Braum is much more of a problem right now due to his mechanics allowing him to force a passive lane and being aggressive himself).
TankRaka had to put herself at risk a lot to make full use of Starcall, having to be at the center of a teamfight and in order to be a viable mid laner she required the right set of runes (get it wrong and it could cost you the lane).
Anyway, I hope that if she gets to see a rework soon it will adress these qualities that made her a special mid laner (being able to support the team), give her a more useful passive (I don't know, this more recent passive doesn't even feel like a good passive for a support - I could be wrong though) and make her a more viable pick as a support.