Thats exactly what I have noticed with 6 core
Big hype about speed and test programs, but in real life
8 core crushed 6 core in lightroom (a true multicore program for exports) resize from raw and export to half size jpg and resize 2000 images from 26 Mb each to 500kb each
50 gig of folders took just over 62 min where 8 core westmere took less than 47 min
OK 6 core had 24 gig of ram where 8 core had 48
but still very impressive for 8 core
Both systems where asked to run Time Machine new complete back from zero at the same time
both 1 gig drives had 400 gig of files on them
Like I sad maybe in a day to day aps like aperture or photoshop may be faster, maybe even in regular edits in lightroom
but when asked to perform to max core thread output
more cores meen more power
BTW I have not noticed difference between the two 6 or 8 core just working in Aperture or Photoshop
Even using NIK or NX2 software was not a big deal they both worked with the same speed
If one was slower not by much
Since I work with very large amount of files export import and work on files at the same time more cores is much better
I know 12 or soon 16 will be better but for now 8 will do the job
for day to day use my 3.06 imac was as fast as the 8 core MP.
I had 6 core for less than a week and it went back to the store as it almost was a fast as my new 27" imac running with 16 gig of ram
When talking to apple they recommended a min of 8 core to notice a difference
If you ever had to wait for some exports to be completed before you can do more edits you will know
and i'm not talking about single file edits
I'm talking about editing 50 files or more at once