picked up the 870 extreme 3, and would like to share my experience with it so far.

My current system consists of

Phenom II x2 555 BE w/ Xigmatek HDT-s1283
Gigabyte GTX260 896 (Factory OC)
4gb Gskill NT 1333mhz
Thermaltake Toughpower 600w

i think everything else is pretty irrelevant :D.

i started off by using OCCT to test overclock

tests are done in OCCT (large data set, infinite testing type, run for 20 minutes)
16x200 1.4v 2 cores(stock), pass, max load 45.5C. 3.2ghz
16x200 1.4v 4 cores, pass, max load 58C. 3.2ghz
18x200 1.4v 4 cores. BSOD. 3.6ghz
18x200 1.4125v 4 cores. BSOD. 3.6ghz
18x 200 1.45v 4 cores. BSOD (after 17 minutes). 3.6ghz
Bios update (P1.50 to P1.60)
18x200 1.4v 4 cores. pass, max load 57C. 3.6ghz
19x200 1.4v 4 cores. BSOD. 3.8ghz
19x200 1.425v 4 cores, BSOD. 3.8ghz
19x200 1.45v 4 cores, BSOD. 3.8ghz
Realised CnQ was enabled
18.5x200 1.45v 4 cores, pass, max load 63C. 3.7ghz
19x200 1.45v 4 cores, pass, max load 65C. 3.8ghz
when i had more time i gave it another shot to see how far i could go. used intel burn test this time around.

Intel burn Test, standard, 10 runs
16x220 1.425v 4 cores, pass, max load 60C
16x230 1.425v 4cores, pass, max load 61C
Dropped HT link to 8x (1920mhz)
Dropped Memory clock to 1280mhz
16x240 1.425v 4cores, BSOD
16x235 1.425v 4cores, Pass, max load 62
17x220 1.425v 4 cores, pass, max load 66C
18x220 1.425v 4 cores, BSOD
18x220 1.45v 4 cores, BSOD
17.5x220 1.425v 4 cores, BSOD
17.5x220 1.45v 4 cores, unstable (reported by IBT)
17x230 1.425v 4 cores, BSOD
17x230 1.45v 4 cores, BSOD
17x230 1.475v 4 cores, BSOD
16.5x230 1.45v 4 cores, Pass max load 61C
16.5x235 1.45v 4 cores, BSOD
16.5x235 1.475v 4cores, unstable (reported by IBT)
18x210 1.425v 4 cores, pass (temp not recorded)
18.5x210 1.425v 4 cores, BSOD
18.5x210 1.45v 4 cores, BSOD
18.5x210 1.475v 4 cores, pass, max load 67C
after a bit of playing around i found the llc adjustments something vicious. cpu-z was reporting 1.58 on loads :L so i've got it at 18x200, 1.45v. kinda bummed i cant break 3.8 without it getting too hot or damaging.

my only issue with the board so far is LLC in the bios. i was pretty confused at first, setting it to "disabled" put on the adjustments, an extra 0.0125 to 0.11v. setting it to normal removed the adjustment altogether. otherwise its been a pretty solid board so far