I'd be willing to try out ElvUI for a bit, but I'm pretty spoiled by my 3x4 action bar grids that keep my brain straight when using my naga mouse.
Elvui has very advanced options. The least of which you can resize your action bars to 3x4, 2x6 or whatever you want. One thing I do with my action bars, is because I'm a lock I have actionbar bloat. I have cookies, summoning blah blah blah. I put all those on a separate action bar, which elvui allows me to fade out of combat. In fact, I'm pretty sure with elvui advance (plugin for elvui) you can fade out anything you want.
Also, Elvui has skins for all the major addons builtin, and you can even do cool things like half bar skins for DBM/BigWigs or integrate Skada with your right chat window. It has a plethora of options for customizing if your into that stuff.
Right now all I use is Skada, BigWigs, ElvUi, and WeakAuras. I'm even in the process of setting up enough macros in WeakAuras so I can literally hide everything except weakaura timers and raidframes in combat. It's pretty damn cool.
Oh I also use Zygor because I'm a completionist and when I can't find something to do I like to go mount/pet hunting and Zygor is just awesome for that. Also when you see somebody with a cool mount you can click on them and click on the zygor button and it will pull up a guide on how to get that mount.
Yep WoW UI is still shitting on the competition. Why nobody has copied it is beyond me.