While I will admit my Transformer Infinity is Tegra 3 powered, my personal opinion is that NVidia is absolutely a horrible company and their products are mainly powered by hype.
As for why I think the company itself is horrible, well....lets just say the majority of my rigs growing up were 3dfx powered.
Anyway, from what I've heard, the famous "Tegra 3" power is mainly hype, its (perceived?) performance gains mainly the result of projection from their success in the PC 3d accelerator industry. Their competitors, the PowerVR and Adreno GPUs, have apparently been able to consistently go toe-to-toe with Tegra performance-wise, and even surpass it in some cases.
If this were not the case, we would be seeing a repeat of the PC industry, where we have an NVidia GPU getting 10x the speed of any other GPU from the get-go, with the exception of ATi, and everyone else consistently being 3-10 years behind in performance or features.