3D power wise, the Droid X is probably the quickest. I can't say compared to the iPhone 4 but it is no slouch. It is without a doubt the fastest GPU in an Android phone to date, making it the quickest graphically (the 1GHz CPU helps as well) but I do not have knowledge of the GPU capabilities of the iPhone 4. From what's been shown, my educated guess is that the Droid X's GPU is more powerful than the iPhone 4's but I can't be certain so don't take my word. But don't worry, it's not substantially slower than the iPhone 4 by any margin so, with the proper coding, this demo could be pulled off on the Android platform. Then again, anyone who optimizes this well could do it eventually. Still, don't worry about the X. It's plenty fast in the GPU and CPU department. As of now, on Android 2.1, it is faster than the Evo 4G in the benchmarks and the Nexus One (running 2.1) so when Froyo hits it later this month, with the Delvin coding that guarantees 2 to 5 times greater performance, it will be the flagship for speed in the smartphone market. Don't worry, it's plenty adequate