But that could just be due to more memory being handled by my early 2009 Mac Pro than prior to switching to this.
Upgraded its single 2.66 GHz 4-core cpu to 3.46 GHz 6-core processor, and figured I'd take advantage of opportunity to use faster (1333MHz vs 1066Mhz it came with) memory allowed with the firmware update that basically turned the Mac Pro into the equivalent of a Mid 2010 model.
But nothing really changed, maybe just a teeny bit slower with the memory benchmarks. So either more memory made the small anticipated performance bump a wash, or perhaps the firmware update doesn't really take advantage of the faster memory speed after all with my hardware.
Regardless, if nothing else I now have more than twice the amount of memory I had before. The CPU bump has definitely perked things up, GUI behavior nice and smooth with Yosemite, though slightly better graphics card may also be helping with that. (Prior to all this, the early 2009 configuration I had was a bit sluggish overall and hesitated a bit here and there prior to doing some GUI activities. But no longer the case, mostly... getting Excel 2011 to do anything faster is apparently just never gonna happen.)