Honestly the Q9300 is a poor chip. With its very low multiplier and low L2 cache it makes for a poor performing cpu. I would go as far as saying the Q6600 is a better chip even if the price was even. If you are comparing Q6700 -> Q9300 the Q6700 wins hands down.
If you are set on the 45nm series, get the 9450. Microcenter has them available online for only $299 (difference of 20 bucks compared to the 9300). Well worth the extra couple dollars.
if you looked at the reviews a few sites, they directly compared the Q6600 to the Q9300. the Q9300 won not by much though, in that comparasion. Q6600 has the better bang per buck but the Q9300 is the better cpu. reguardless of L2 cache, in gaming the double of L2 = 6% increase in gaming. all other areas are not effected by L2, the only other programs that would benifit the extra L2 are programs like SETI/FAH.
in a server situation depeding on what its doing, the other parts of the pc will be the bottleneck. things like data serving will be on the Hard drives and network, more then the cpu.
nvm i missed that in your first thread. you wont see a big difference in a q9300 vs q6700 for doing SQL.
The slightly higher clock speeds of a Q6700 doesn't make up for the fact that the Q9300 is faster clock per clock. The Q9300 is the better CPU but the older 65nm quads are cheaper and so can be a better buy.