Tales of the Valiant and D&D2024 both set out on similar missions at about the same time - to improve aspects of D&D2014 without invalidating previously published content that both companies hope to continue selling. They ended up with some cases of convergent evolution, some overall power increase while nerfing a few power combos, and each of them had areas where they were cautious and conservative and others where they innovated.
(basis for comparison: I'm a professional GM running ToV tables, D&D2024 tables, and mixed tables)
Places where I think ToV shines:
1) Luck. A fabulous mechanic to replace the always-forgotten and way too subjective Inspiration. Even if you don't play ToV, steal this rule.
2) Lineage-Heritage-Background-Talent. The character creation process has more interesting options and decisions, resulting in much more varied characters even at first level.
3) Monster design. This has always been a Kobold Press strong suit, and the Monster Vault made every single iconic monster cool in some new way.
4) The mechanist class. It feels more like a gadgeteer than the artificer ever did.
5) Making rituals a separate silo. These are spells for non-combat situations mostly - downtime, exploration, investigation, social. Shining a spotlight on them encourages both GMs and players to pay more attention to that part of the game.
6) Taking that starting +2/+1 to stats and putting it.... nowhere. Just start with higher stats. Done. Along with giving three talent options with each background, this further opens up character building. By contrast, 2024 in some ways just moved the problem points. In that system instead of every X class needing to be Y species, every X class needs to have Y background. All monks must be sailors, because that's the only way to start with Tavern Brawler.
Places where 2024 did a better job of innovating than ToV:
1) Rewriting spells. ToV was too cautious about tinkering with spells and adding new ones, which surprised me considering the crazy broken stuff they put out in Deep Magic 1 and 2.
2) Fixing some problem rules. Simplified exhaustion was great. Removing most opposed roles (grapple, etc) saves time.
Places where both ALMOST got it:
1) Weapon options/ Weapon Mastery. 2024 gives always-on effects to different weapons, and only martials can use them. ToV gives choices to either apply an effect or hit for damage, and all characters can use them. 2024 is, after the novelty of knocking a creature prone every single time you hit, not a solution to combat monotony. You're still doing the same thing over and over. ToV locked too many of their effects behind a double success gate - you must first hit your target, then they must fail at a save, for your brave move to do anything. My solution is to keep the ToV options but drop the saving throw requirements; they work on a hit. Giving up your damage is enough penalty without making them usually-fail options. (Note: this is at least the third Kobold Press version of weapon options - Midgard Heroes Handbook, Tome of Heroes, and now ToV. MHH was too strong, ToH about right, and ToV a bit weak in my opinion. But the fact that all 3 are published lets a GM fine tune a weapon options suite for their table).
Places both failed:
1) Mounted combat. It still sucks and no one tried to fix it.
Specific classes are definitely more powerful in one ruleset than the other. The ToV bard and ranger, and the 2024 barbarian, for example, are clearly a cut above their cross-system counterparts.