Importance of AWA score

I would say the use of the IR score is "too be determined." I say this because this is the first admissions cycle where IR scores were reported, so there's no real history. Also, people like me who took the GMAT in 2011 and applied this cycle don't have an IR score and we can't be penalized for that since scores are valid for 5 years.

In my opinion, I think it's going to be 2-3 years before the Adcoms decide how important the IR score is, and I can't ever see it being more important than the Verbal and Quant portions. I figure it'll be similar to AWA where once you reach a certain score, it's "good enough" and you don't get any bonus points being higher than that. What that score is remains to be seen.

Agree with CobraKai here, apparently a whole lot of schools are disregarding the IR this year to see how it shakes out, among them is HBS from what I've read.
The one thing that schools can use the AWA for is if you have a huge difference in quality of essays and your AWA response, they can be compared. The school has access to your AWA response

Agree with CK. And I'll make a fool out of myself (because I dont have anything to back this up) by saying, you will be absolutely fine with 6 on 8.