I played Zyra alot in S2. Main mid in ranked and around 75% wintrate- she was kinda OP in mid, yes.

however i never had problems with her as supp. Rly dangerous is her lv 6 burst if she lands her e, but that falls off if she doesnt get gold/assists/kills.
The utility with brushcontrol is rly nice, sure, but i think if you are just cautious against her from 6 on, shes not better than other supps.
Shes just nice and bursty. If she gets some ap she even has even good damage later, but nothing to complain about i thnk.

My experience as support is she's a lot of fun. I've done maybe 40+ games with her in unranked and she starts of strong when you're aggressive, only has to buy one ward allowing for more pots making laning easier. And late game you can build her to do okay damage that sometimes gets you kills, or if needed you can do full support items if others aren't. But her dmg items are also supportish so it really has nice synergy when you go dmg.

Cho'Gath is being seen jungle and top, plus a couple times mid. Many AD assassins and AD casters are seeing similar versatility. Zyra isn't alone in this. However, she is a totally boss support.

Zyra is a great match up in ~any lane~ with a LOW MOBILITY opponent. The amount she photosynthesizes over Draven and Miss Fortune is nothing short of embarrassing.

I use her alot as support and I've had games where I went from being support to being the one carrying the team, with the most damage to champions, most kills(not taking them from the adc during lane phase if i can help it) and the most gold overall. Where she crushes most other supports is that with 2 seeds you can easily wipe out minions mid game that would normally be missed (golems/wolves when your jungle is ganking top) as well as burst down and control the enemies in lane. At level 6 if you catch the enemy with a root under the tower you can easily combo, ult and set your adc to get free kills as they fly through the air and the tower focuses the plants. She bad early (level 1-4) but 5-11 you can solo and almost insta gibb an adc or squishy support like sona.

I met a lot of "support" Zyra who went to another AP carry at late game, aye aye, good damage, but, OMFG, Wards!!!!, none of them bought a single ward for the team.
OT: She's good at support, snare, good damage, but people need to know that if they wanted to be a support, then go for support items, not another AP carry.

She a off version of Heimerdinger

Thank you for all of the replies and tips folks

So I've done some of my own testing, bought her and had some games with her on a couple different accounts. I've noticed, whilst playing Mid anyway - that she seems to be more of a Harassment Tool than a sheer killing machine, pre-6 anyway.

The abuse of Seeds and her effects on them seems to be quite annoying for people to play against, and once she gets her Ult - Teamfights become a battle of attrition for other people as soon as you time it with another AoE CC Ult. Her burst becomes quite noticeable mid to late game.

But even then I find her skills are more in-tune with being combo'd off of other Champs. I mean yes I can kill someone outright on my own, but it almost... feels, like a waste of her skills you know? I mean sure she has CRIMINALLY low CDs, which I love lol And her mana costs are pretty damn low too, so it's not a huge detriment to blow a combo on one Champ but..

God it's so much more beautiful when you unload it all in the center of 4 or 5 people.

I DON'T main her, so my words might not be of any value to you, but I really enjoy her as a mid. It's extremely skill based, and the ambush possibilities are fun as hell. <<Just my opinion, very high skill cap on her As a support Zyra, I like it, but not enough to play it when I could play Alistar, or someone I deem more fun. All in all, her support role is fun, both are viable and fun, and she's an amazing champ all around.