When it came time for comparisons, I was more interested in the green/grey issue than finding a dupe, so I pulled out Rescue Beauty Lounge Orbis Non Sufficit, which is undisputedly green, and OPI Suzi Skis in the Pyrenees, which is definitely grey.
I used two coats of Orbis; surprisingly, I needed three of Suzi Skis.
Even next to a green, Power Clutch looks grey to me. That's not a problem; I like grey polish. I just ordered the rest of Essie Fall 2011 from AveYou (not affiliated) with the 50% off gift certificate deal from KGB Deals (that's a referral link for me, but I just signed up this week so am not sure how it works exactly), which I found out about thanks to the ladies on the MUA nail board.