"A Google machine had the fastest time in 13 of the 14 tests...Google was also the cheapest overall [...] 3.78 cents on Google,[...] and 5 cents on Amazon." http://www.infoworld.com/print/237169
Just between us, we're not happy with our performance. We had to make some compromises to get Compute Engine to General Availability last year, and we aim to do better in future releases. Still, nice to see we're competitive already.