Summit, after slowly and still not done yet, working through 1/2 lb of it, it's a garlic onion soup party when used by itself late in the boil, or during dry hopping when it's the most prevalent of the hop bill. However, Nathan Smiths dankness, which used Summit heavily and for dry hopping rocked, and I didn't pick much if any onion or diesel fuel notes I normally get with Summit. Highly recommend that recipe.
This shows that you can percieve the onion/BO aroma and second, that it can be put into check by balancing a blend with other hop varieties. Also, I have never dry hopped with Summitt alone, but I think Oscar Blues Gubna is all Summitt and I don't get onion/ BO out of that one myself. It's robust, hoppy and dank though.