I recently came across a whitepaper from Teradata, written by a senior consultant for Teradata, Richard Burns. This is a very well written piece, and has one of the best overviews of Exadata I’ve seen. I did not notice any obvious inaccuracies in the description of Exadata itself, and even the anti-Exadata arguments (presented after the overview), though at times biased and misleading, do not have many clear factual errors. Hence, it is quite a professionally done whitepaper, even though it is devoted to attacking a competitor. Reading it will probably make you smarter.
Both the original whitepaper and Daniel’s commentary are worth your time to read.