I know the 9X multi is great and coupled with great Ocing capabilities it's the only killing feature of the E4300. It's great for overclockers, however, making a bit of price analysis, buyers mostly don't spread in spectrum; If you want to buy a good dual core CPU and you want it cheap, you start around $100 (the 3800+ is sliding here), pass by the $140-160 mark (E4300) but if you spend around this amount, you start sticking aroud the $200 of the E6400; good multi, better perormance/clock than the 4300.
It's not that I don't like the 4300, it's just that it's somehow in the middle; more pricy then the cheapest options and slightly less than a really good option.
The X2 3800+ is $140, not $100. The E4300 should come down to around $165 once the price gouging ends. The E6400 only has an 8x multiplier, and costs $220. Performance/clock advantage vs E4300 is almost non existent. A faster FSB does next to nothing for C2D, unless you're the type to get excited over a 2% performance increase.
http://anandtech.com/cpuchipsets/showdoc.aspx?i=2795&p=6
Let's see the requirements for a 3.2GHz overclock for the low end C2Ds:
E4300 - 355MHz FSB / DDR2-710
E6300 - 457MHz FSB / DDR2-914
E6400 - 400MHz FSB / DDR2-800
The E4300 has by far the least stringent FSB and RAM requirements.
I've said it before and I'll say it again - the E4300 is by far the best choice for a budget overclocker. The savings you get from this chip extend far beyond the CPU price alone - you can also utlise cheaper RAM and less expensive mobos. Some of the cheaper P965 boards simply won't overclock much past 350 - 400MHz FSB.
Obviously, at stock speeds, it's not that exciting, as it essentially slots in between the X2 3800+ and E6300, and lacks VT as well.
It's great for us budget overclockers, especially when overclocking ram costs a truckload!