Which Mac? - Help!!



I was looking at the 8-core Mac Pro, but my budget will not permit this. :(

If I take expandability out of the equation, will I get more bang from an i7 iMac, or the 4-core Mac Pro? They are both 4-core machines.


I don't know which is the best bang for the buck of the two mentioned.
The problem is that your budget in the long run (within 2-3 years) probbably would benefit from the more expensive solution. I have just ordered the 8-core and will then send my G5 on retirement, it lasted 5½ years.
A friend of mine who insists that he won't buy the bigger models (and in his case it's not his budget that won't allow him) has spent quite a bit more than me over the last 5½ years because the smaller models just don't have the headroom (in terms of cpu) to last for 5½ years so you will be forced to upgrade too often (but then again, that depends on what you do and how you do that).
Like the previous post said the more ram and cores the better, so in "almost" reality 8-cores are twice as efficient as 4 cores (which means 100% more power for an extra $1000). So why didn't I buy the 12-core.... It because I find that paying $1500 more for only 50% more power may not make finacial sense in the long run.
At this point (and for a long time to come) the 2.4 8-core is easily fast enough, and when it gets too slow, will the 12-core last long enough to make it worth the extra 1500 dollars? I doubt it but I still almost bought it just because I almost couldn't help myself:)