I'm a huge fan of the Oppo 981. Its upscaling is breath-taking. Its upscaling of DivX is remarkable. Basically, it offers a stunning picture, easily fooling the eye into thinking you're watching HD on very well transferred DVDs. Plus, it does SACD and DVD-A, which the HD-A2 doesn't do.
I have no interest in the HD on disc thing until a clear winner emerges, so I went with the Oppo 981, and when I look at the picture quality, I have no regrets.
cheers,
supervij