well I chose the E8500 over the Q6600 in 2008 and was glad that I did. in 99% of games the E8500 was as fast or faster and it used less power. by the time the Q6600 started looking as good, we already had new cpus coming out. sure the Q6600 could be overclocked but it was a very power hungry cpu when doing so. and with the E8500 also oced a bit, the typical oced Q6600 still lost nearly all of the time because MOST games just needed 2 really fast cores. there were really only 3 or 4 games that I played in over 2.5 years where a Q6600 would have provided a better experience.
Well even at 3.8ghz overclock and say 10% IPC improvement that Wolfdales had, the
$299 E8500 @ 3.8ghz would have been only about 16-23% faster over a 3.6-3.4ghz E6600. The problem is E6600 launched at nearly that price almost
2 years prior to that! You have to admit the E8xxx series were not good value, and the performance increase they offered over the E6600 overclocked 20 months later was sub-par by today's standards.
Consider this: It was more than 1.5 years between E6600 and E8500 for a pretty small performance increase (I mean we are talking less than 25% with overclocking on both). Just 8 months after Intel launched the $299 E8500 (2 core) series, they managed to launch the i7 920 (4 core 8 threaded CPU) for
$284. In other words, Intel was literally selling a CPU with at least 2.5x the power for less $ than the E8500 in a period of less than 1 year.
Your 2500k won't suffer the same fate that the E8500 did (i.e., Intel launching an 8-core 16 threaded CPU in 1 year from now for $300).