I don't have near the experience with these two bullets that some do here, but I'll add my two cents... I've only shot them this year (Bergers Gen 2s) and last year (SMK 300g) out of a 338 AX (338 Lap Imp) at 2976fps ave. (Berger--101g Retumbo) and 2980fps ave. (SMK--102g Retumbo).
Last year with the SMK, my shot ranged from about 360-380 yd on a 4x4 Muley and spike elk (good hits that dropped both dead on impact) and a 445yd, approx. 200lb. black bear (high shoulder)--also dropped on impact. The elk was fairly steep downhill shot that went through part of the spine and then shattered the offside shoulder.
This year, I'm shooting the Berger Gen 2 and my general sense is one of greater precision than the SMK. I'm seeing closer, more consistent grouping at lr shooting for groups on paper and steel out to 1000yds (would advise anyone to do this and not just shoot rocks--check out your groups on paper and/or steel.) Coupled with a bit higher bc, it seems to be a better candidate. On 9/23 I shot a smallish 4x4 Muley at 580yds, 15 deg down and on 9/28 shot a decent sized bear at 741yds in about 11mph winds.
The deer was at an angle (with light fading fast) where the bullet entered a bit back (my fault) in the ribs and blew a huge exit hole on the offside with internal organs sticking out. No pics as is was dark and I only had a cell phone with no flash. I was by myself back in designated wilderness in grizzly and wolf country and working fast to get the meat out of there. Bang, flop.
The bear last week was at 741 yds with about 11mph wind. Bullet went exactly where I held, but I adjusted the windage knob 2.5 MOA R and also thought about the air that the bullet would be shooting through compared to he air I'd measured and ended up holding probably 4-5" further R. Instead of high shoulder, it got double lunged and went about 30yds before flopping. That bullet appeared to go in and out between ribs and the exit hole was just over an inch, but the bear was quickly dead, so...dead is dead. Also, by myself in designated wilderness and trying to get he meat out, so didn't spend the time to do and autopsy and I used the 'gutless' method anyway, so... Would recommend hitting high shoulder bone to help initiate expansion, but that is just anecdotal from one experience.
2011 Washington Bear
Also check out Shawn Carlocks work here comparing these two bullets:
More Berger 300 Hybrid Gen 2 testing
Berger Gen 2 ELR testing
Berger 300 gr gen 2 penetration testing