I did a rather extensive review on it when it first came out. Used one exclusively as my EDC and KP knife for a month, to compare it to the Stretch which, since its introduction had served as my primary knife for both those purposes. Was really excited over it, because the Stretch, while a great working knife, is (at least to me) one of Spyderco's less attractive designs due to the "hunter" blade spine shape.
Short version - love the look of the R2, and it feels great in my hand once opened. Fit and finish are excellent, especially considering the price-point. As expected, cutting power was more or less identical to the Stretch, as the blade steel and grind are the same, and the edge curvature is very similar. "Deal breaker" for me was that the thumb reach needed to open it was considerably greater that that of the Stretch, and was not really comfortable for my short thumbs. Other minor gripes where that both the blade and lockbar pivot screws kept working loose, it took "industrial strength" loctite to stop them, and that the clip was not lefty friendly.
The last, is not a biggie for me as I take them off anyway, just a matter of principle. But it may reduce interest in it by other southpaws. Considering that a disproportionally large percentage of the most active participants in both Spyderco forums are left handed, that may be a major reason for the minimal amount of commentary on it.