Updated to 2.2 from builds.firefoxos.mozfr.org/doc/en/devices/zte-open-c-eu and it has been wonderful. copy and paste are shrink-able app stack are great for sure. More importantly, the merging of browser and the OS is so much more seamless. Tapping the universal search on homescreen now does apps, suggestions and histories, much like desktop firefox awesome bar on steroid.
Very good update, and judging by the comparison of original modUI of this post, and the more recent build at mozfr, the optimization mozilla made is tremendous. Can't wait for the final release!