FWIW... my opinion.
it gives an insight in the different architectures of intel.
Then think about what is your goal. The example above is an intel doc for CAD computing. So this is far heavier than audio processing.
Spending heavy amounts of cash on expensive cores is one thing. It is not every time the best solution for DAWs, certainly if budget is important. An expensive system needs to be alligned overall.
example taking from the internet:http://www.adkproaudio.com/choose2.asp
An alternative option is to spread the resources over multiple systems and link them.
Look for software like this:
This software is add on for a DAW like cubase and makes a network of computers but they are handled within the DAW that acts as a master. The other systems are slaves.
It gives you an opportunity to go into some direction without spending all at once.
drawbacks: more workflow to learn and more dongles are needed (but a dongle is cheap)
also watch out for internal graphic cards of the i-family processors. For the moment they are stable since the last update, but when graphics need to be handled by the processor, this can interfere with the audio processing.
choosing between xeon an i7 is like choosing between fiat and bmw. So yes xeon is more stable, has broader pipelines, is build for servers and thus more durable, and so on. The price tag is likewise.
but with an i7 you can run 50 vstis nowadays without any problem within cubase as long as you take the core handling into account. (never do too much within one vsti, since it will blow a single core and blow your performance, and leaving a lot of power unused)
so hope this gives you some starting point. I hope others on the forum with studios will jump in and guide you towards more...