I tested several open source keyboards last year looking for a way to get rid of the distracting gif search in gboard, and was also very disappointed and went back to gboard. After trying this one for just a couple minutes, this looks much more usable than those I tried last time. I don't use voice texting, and mostly just need decent swiping and prediction. I'm hoping this will meet those needs!
Of you are looking for swipe support only AOSP and and AnySoft gave good results for me. There certainly are some other swipe keyboards, but most feel broken.
There is Heliboard which I currently use. It supports loading the AOSP IME modules for swipe so it is as perfect as AOSP. It also supports multilingual typing.
