Aloha is more than a meg of JS as it stands and the documentation is pitiful.
Main issue with the documentation was the rapid changes to the API in the past. Since the API is getting stable there will be more concern on improving the documentation.
It should be noted that we plan to make the ui an optional part of Aloha (with default being a jqueryui implementation) to make it easier to integrate into existing systems. The heavy extjs dependency is part of why Aloha is so huge.
I also plan to look into using google closure compiler in ADVANCED_OPTIMIZATION mode to shrink the size to the absolute minimum.
I stand by my comment about the lack of documentation though. I appreciate that it’s often difficult to get people to contribute to docs over code, but it’s pretty imperative for a project like this that there’s at least an easy integration walkthrough and a handful of examples showing common customisations.