@Adam: I think it might be useful for you to post a comment giving a brief explanation of what the whole "mining" thing is about. A lot of folks who aren't familiar with this area may be asking themselves "What does this actually mean?"
The limiting factor in your comaprisons should be - the price of the most expensive system [Zedboard]. DMIPS are nice, but DMIPS per dollar appeal to finance sections. If you can buy more than 3 Pi's for the cost of the Zedboard, the performance factor you noted for the Zedboard becomes irrelevant.
If you need the FPGA section to totally thrash the competition, what happens when you give the competition an FPGA too?
So, I'd like to see a Beaglebone Black [BBB] thrown into the comparison mix. Then I'd like to see some kind of FPGA add-on for the Pi and BBB, such as the Logi-bone. The comparison of a Zynq system to a BBB [or Pi ] with a humble Spartan-6 "tacked on" would be... interesting.