[Champion Discussion] Is Zilean Worth Playing?

Hey Everyone,

So I've been thinking of playing Zilean, but I'm having trouble deciding whether I should pick him up or play (what I think) is a similar champion; Kayle. Right now, Kayle seems to be at a decent spot, Riot reversed some nerfs on her a bit, which seems to show she's closing in on a balanced state. Zilean is sort of a rising FotM pick, gaining a lot of popularity in the mid lane since Faker's been playing him. Both of them are fairly easy to learn, having all targeted abilities, and have a lot of utility, namely a teammate saving ult.

One of my main concerns with Zilean right now is that he may be at risk of being Soraka'd/Lulu'd. Zilean is already slated for a rework, and his recent popularity in mid lane is concerning. I'm not sure what Riot's intention for Zilean is, but I think he's supposed to be more of a support pick, and that he's been shown to be a pretty powerful mid-laner might cause a gut-until-rework change, sort of what happened to Soraka, or a nerf-into-support, like what's happening to Lulu. I don't think Zilean is as oppressive in lane as either of those two, but it's certainly a point of concern, I think.

The benefits of Zilean (over Kayle) is that he has increased range, plus, even though his abilities are very costly, he seems less likely to go oom (he usually builds more mana or mana regen, unlike Kayle, who might just have a Lich Bane at most). He has arguably better team saving ability since his ult grants health back and can be on a pretty short cooldown from spamming W. He has much better burst damage, since his Q does a ton of damage (320 base plus 90% AP x2, pretty insane).

Benefits of Kayle: I already own her (yea I know, 1350 IP isn't much to spend on a champion, but I have a lot of champions on my wish list and would rather save IP for champions that I'll actually play a lot, unlike some other FotM picks cough Twisted Fate cough). Kayle also has a stronger late game, where I've had some problems in the past with mid laners who have good early and mid games but have more trouble/transition to more of a support in the late game (Karma, Lulu).

Do you think Zilean is worth picking up? Or does Kayle fill that niche well enough? Thanks!