I just tried the GEL on my nexus 4 and it is very nice. Having the OK google right on the home screen is cool. Very easy to install. Some people don't like the larger icons. But overall I like it. No longer nexus 5 exclusive.
YepYep I Love the GEL ever since I got my Nexus 5 and I've ran the GEL on my Nexus 4, my Moto G and even on my Nexus 7 2013. The only issue I've had is with it on my N7 2013 in which one of the dock icons keeps disappearing when I reboot the device and it happens No matter what app I place in that spot. Overall though I Love it and it's probably my favorite launcher in a tie with the Sense 5.0 and above launcher which is very similar to the GEL but instead of the Google Now page it has the Blinkfeed homepage.
Have you had any issues with icons disappearing?
So far no issues with icons disappearing. I do somethings have a issue with the OK google not working on the home screen. But I go to the Google now screen and then back to the home screen and OK google works again