I've used the Fed. High Energy 300 win mag ammo and it shot quite well. I can't tell you about the 308 stuff. i was waiting to see if anyone else responded & they didn't so I thought I'd just tell you what I could. Good luck!
From an accuracy standpoint you will not likely find any .308 HUNTING ammo that will compare with Gold Medal match. I have only chronographed Federal High Energy in .300 and .338 so cannot give any input on the .308, other than I am confident that it will not group like Gold Medal.
High Energy ammo does have higher velocities just like they claim, but I have not found it to be super-accurate in the magnums - usually about 1 - 1.5 moa in my sporter weight rifles.
Partitions are reliable hunting bullets, usually retain about 65% of initial weight. Not sure how they would act in a .308 at long range.
Longest shot that I have made so far with 175 gr. Gold Medal was 322 on a feeding doe - did a perfect job. It is significantly flatter out at 800 - 1000 yards than 168 in my rifles.