I don't really want to self bump shamelesly, but all the Sona nerfs justification have started to turn into BS by themselves lately.

The knockup is like .2 seconds.

The CC portion is dependent on ally positioning and smaller around that ally, making it easier for enemies to avoid situations where they get hit by it. In addition, it doesn't last as long and isn't as AoE.

I just thought of amumu initiate followed by a LuLu ult. OH YEAH!

As a Sona player, I would point out that Sona is the only support character that can safely initiate a teamfight. Janna's tornado doesn't last long enough to initiate with, and she'd have to do a risky flash ult to initiate with monsoon. Alistar has to jump into the middle of the enemy team to initiate. So does Leona. Sona can sit back just behind her main aoe initiator and launch her ult to nicely set up the second aoe cc.

Lulu's ult is going to be disruptive but you won't be able to really initiate with it. More of a secondary CC like Janna's tornado, with a persistant but short range slow centered on your tank.

I think the main difference is that Lulu's also requires an ally. The CC is much weaker than Sona's, of course, but it's also much more of a support spell than Sona's ult, as it has to be cast on an ally who is already in the fray.

It does have knockback, just a small one. Watch around 2:10 and look at where champs launch within the particle effect aura and where they land in (and out) of it.

It's small, and maybe only enough that melee champs would be the only ones to get annoyed by it, but it is there.

The total disable time of her 'R' should only be about half a second or so - which is kind of a waste if you're using it to chain CC a team. It also doesn't do any damage - but the slow component is very heavy, I agree. However, it doesn't take the enemy team's ability to fight back (and fight they must now.) Put it another way, if you were to string 3 of Lulu's ultimate's together, you'd then have Sona's ultimate in CC length.

In my statement on Sona, I very carefully stated that the problem isn't AoE CC (Otherwise, Janna's ultimate would be problematic and I would've said so) it's about AoE "Lockdown" CC primarily designed or used to lock down the enemy team, preventing them from taking actions (or can be chained with each other). Howling Gale, for instance, is a huge AoE CC on Janna. However, actually using it as part of a Lockdown string is kind of a waste, as the interrupt value of it far exceeds the chain stunning value of it.