Nova isn't just a launcher anymore, it's become somewhat of a tech cult. Not that they didn't earn the kudos they have, just pointing it out. Which is why I'm going to be accused of blasphemy for what I say next - I'm sick and tired of those AOSP style launchers. Nowadays I turn my attention towards... heck I don't know what the term for them is... feature launchers I guess? Contextual launchers? "Smart" launchers? Right now I'm using the 2.0.3 version of Aviate and it's every bit as fast and smooth as Nova/Apex now since that latest update. The RAM use seems to scare some people for some reason (I suspect lack of android OS knowledge). It usually shows up at around 150 MB in running apps. However considering recent devices are at 2GB and up now that's not an issue. You certainly don't detect anything amiss performance wise.
What many AOSP launcher users dislike about these 'smart' launchers is there's less customization. However that can also be a pro for people like me who are totally burned out with too many hours spent buggering around with Zooper widgets and complex layouts. Aviate looks pretty sexy as-is and still lets you do a modest amount of customization. One thing I noticed was that a combination of multiple Zooper widgets and Nova Launcher actually lagged slightly more on 2013/2014 flagship specced devices than using Aviate on its own. I've tried Everything Me launcher as well and wasn't impressed (plus it's a little laggy during some launcher settings operations). Nokia Z launcher and Terrain I haven't tried. I hope we keep seeing more of these type of launchers from now on though.