Despite frequently appearing together at conferences, it is fairly rare to see public debate on technology and technique between people from Google and Microsoft. A recent talk on A/B testing at Seattle Tech Startups is a fun exception.
In the barely viewable video of the talk, the action starts at the Q&A around 1:28:00. The presenters of the two talks, Googler Sandra Cheng and Microsoft's Ronny Kohavi, aggressively debate the importance of performance when running weblabs, with others chiming in as well. Oddly, it appears to be Microsoft, not Google, arguing for faster performance.
Making this even more amusing is that both Sandra and Ronny cut their experimenting teeth at Amazon.com. Sandra Cheng now is the product manager in charge of Google Website Optimizer. Ronny Kohavi now runs the experimentation team at Microsoft. Amazon is Experimentation U, it seems.
By the way, if you have not seen it, the paper "Online Experimentation at Microsoft" (PDF) that was presented at a workshop at KDD 2009 has great tales of experimentation woe at the Redmond giant. Section 7 on "Cultural Challenges" particularly is worth a read.