Now the question is do you lose any features going to the macpro3,1. I could do that, but my system matches imac14,1
So what would I lose switching to macpro3,1?
I've always used 3,1 actually. because imac defs always gave me weird audio popping issues (like audio was always waking from a powered down state and popped as it powered on, similar to turning on a speaker). with 3,1 this pop never happens, probably because sound loses whatever PM causes it.
Also with 3,1 you can't get true power management for cpu, so cpu geerally sits at either 4ghz, or 800mhz idle. nothing in between. although it does speed step between 4ghz and my 4.6 OC. but since it sits at 800mhz at idle i don't worry about it too much that it ramps up to 4ghz instead of 1-2ghz for meager tasks. You basically can't setup power management profiles for 9x-39x.
Sleep probably doesn't work 100% either but i never use sleep. ever. I've never tired it os maybe it works maybe it doesn't. I haven't on my original mac pro and don't on this. display, hard disks yes. system, never. I always have something or another running.
GPU power management is 100% so no loss there. that seems controlled entirely by nvidia driver.
I don't know whether or not USB 3.0 works or not. I only have usb 2.0 devices. all my my good stuff is on the inside (my two ssds, 10k rpm storage HDD with tons of space). External devices i use my iphone, webcam, mic.
So this all works for me. It may not work for everyone. Others who may not want to give up cpu power management, or usb 3.0 may have to wait for the 17MLB research to get complete. they can risk using the existing generators now, but putting random chars in the fields we don't yet understand is risky business. Plus considering how inaccurate the 13char generators were (generating random stuff for EEE instead of correct hardware class), I certainly don't put stock in the validity of any numbers they'd generate, even if they fool apple for now.
I strive more toward long term solution than random numbers. Because invalid numbers or machine identification could be the next block if syntax isn't doing enough for apple. This is why i went extra mile and ensured:
Apple OEM ROM (imac wifi card i use for wifi/bluetooth/handoff).
3,1 definition with 13MLB and a valid EEE code for 3,1 mac pro that matches definition.
unique serial. Now whitelisted by apple
I hope to see no further problems with the extra vigilance. We shall see!