Alright, so as you know, hyper offense is all about dealing huge damage. Right? You want the 'mon that'll be dealing the most damage. Trust me, in calcs, that can make a world of a difference.
252 SpA Life Orb Latios Psychic vs. 252 HP / 4 SpD Toxapex: 283-335 (93 - 110.1%) -- 62.5% chance to OHKO
252 SpA Latios-Mega Psychic vs. 252 HP / 4 SpD Toxapex: 254-300 (83.5 - 98.6%) -- guaranteed 2HKO
With this, this can make the difference between killing toxapex, or letting it live. Thus, you should go with Latios + Life orb. If you want, I can add more calculations :).
Alright, my old answer was.....kinda crap. Sorry about that. So, I'm going to add more calcs.
252 SpA Life Orb Latios Mystical Fire vs. 252 HP / 176+ SpD Ferrothorn: 291-348 (82.6 - 98.8%) -- guaranteed 2HKO after Leftovers recovery
252 SpA Latios-Mega Mystical Fire vs. 252 HP / 176+ SpD Ferrothorn: 264-312 (75 - 88.6%) -- guaranteed 2HKO after Leftovers recovery
Now, this might not seem like a great calc, but 98.8% + Stealth rock chip can knock it out, but because ferro resists sr, mega latios won't kill it.
252 SpA Latios-Mega Mystical Fire vs. 252 HP / 252+ SpD Celesteela: 136-162 (34.1 - 40.7%) -- 54.5% chance to 3HKO after Leftovers recovery
252 SpA Life Orb Latios Mystical Fire vs. 252 HP / 252+ SpD Celesteela: 153-182 (38.4 - 45.7%) -- guaranteed 3HKO after Leftovers recovery
OK, so in HO, imo, you should use Latios + Life orb. Balance is a completely different beast, however. As you know, latias is a bit bulkier than latios. Here's the thing: Latias is much more common than latios. But not just normal latias, MEGA latias. Mega latias is much better on balance because balance appreciates its ability to actually take a hit. It can rip through an entire team with the combination of aura sphere, calm mind and stored power. The defenses are amazing for it.
252+ Atk Choice Band Scizor U-turn vs. 252 HP / 4 Def Latias-Mega: 320-380 (87.9 - 104.3%) -- 25% chance to OHKO
(This is a smogon set)
252+ Atk Choice Band Scizor U-turn vs. 0 HP / 0 Def Latias: 410-486 (136.2 - 161.4%) -- guaranteed OHKO
Possibly surviving a u-turn from a banded scizor could make a world of difference.
252 Atk Life Orb Kartana Knock Off vs. 252 HP / 4 Def Latias-Mega: 203-239 (55.7 - 65.6%) -- guaranteed 2HKO
Living a hit from a max attack Kartana (not adamant) is insane. However, non mega latias...ain't having that.
252 Atk Life Orb Kartana Knock Off (97.5 BP) vs. 0 HP / 0 Def Latias: 385-455 (127.9 - 151.1%) -- guaranteed OHKO
So, in summary, for Hyper Offense, I would go with life orb Latios, and with balance, I would go with mega latias. Hope this helps :)