Huge price difference but how about performance? Is it really worth the extra cost? I have another post regarding the system this is going into which happens to be a SolidWorks CAD (Drawing, Assemblies, Future Rendering) w/ some part time gaming. Pretty much all around tough computer to replace my existing Olddddd box.
Unless the $970 is easy to dish out, I'd say it's not worth it. For sure it'd be faster but that's a lot of money. Note that price drops are coming on April 22; see here for more details. The Q2 price column means April 22.
Also if you really want a quadcore, the Q6600 is supposed to be $266 at around the end of the summer. So you could always get a fast and cheap Core 2 Duo like the e6420 now, and upgrade to the Q6600 when it's $266 if you want a quadcore.
The bad thing is that I'm in a hurry to get this done as I've been allowed (!!) to work from home part time and need a kick A$$ machine to work with. I'm thinking that I can always move ahead towards the end of summer if need b with a better CPU but really need some power now.
I don't know a lot about SolidWorks but I think it's single threaded, like most CAD programs. So you wouldn't really get the advantage of 4 cores in the Kentsfield. QX6700 is clocked a little faster so it'd perform a bit better due to that, but the e6600 is an easy overclock and would probably overclock faster than the QX6700 could due to heat. Even at stock speeds though the e6600 is a fast CPU.
So I don't think the QX6700 isn't worth it, regardless of whether or not you overclock. Unless I'm wrong about SolidWorks being single threaded, can anyone with experience with it chip in?
If this is really a job related thing and requires the need to work with CAD, I'd get the QX6700 and plan to write the cost off on my taxes. Even if the particular program is single threaded, newer versions will probably go multi-threaded.
If the cpu is not really job related, then the E6600 is a better buy, in my opinion.