Hi Jonathan,
Many Business Schools have publicly stated that they don't use the IR score as part of the application process, but if you would like to know how a specific Program views the IR Score, then you can reach out directly and ask (most School's Admissions Departments will be glad to answer any application questions that you might have). As far as the AWA/Essay is concerned, many Programs expect that Applicants should be able to score at least a 4.0 (out of 6.0) - and that's actually a fairly easy Score to achieve (there are even templates that you can follow).
GMAT assassins aren't born, they're made,
Rich