I'm not IA developer, but upgrading to 8.3 would not be as easy as to upgrade to 8.1.+.
Also, 8.3 doesn't really have an official release date.
Talking for our personal project, we upgraded from 8.1.08 to 8.1.2X (from memory) without much problem. We had to fix some connections and I think that was it. IA does a great job mantining compatibility with older version.
I see upgrading to 8.3 as a "small project" wheter upgrading to sub-versions as an "afternoon project".