Tegra 3 in the Ouya is still faster than a Raspberry Pi 2. (RPi2 is faster than a Tegra 2 though)
My hope was they would release an update of Ouya with the Tegra K1. But that never happened. The SHIELD console has a Tegra X1, but the base unit costs twice what Ouya did, so it's a bit hard to justify the purchase. It's certainly more than twice the performance, but is it twice the fun?