I'm sorry, I can't point you in the direction of any benchmarks, but I can lend some of what I have heard.
According to hearsay, 2.0 currently offers no advantage of 1.0. The reason that this is, is because current games cannot even take full advantage of the 8MBPS transfer. I mean, I suppose it would be fun to say that you are able to transfer at 16mbps, but if there is a large price difference, I would suggest going with 1.0
Hope I helped,