I like to think of 5e as an open platform for lots of RPGs, including D&D 2014, D&D 2024, Tales of the Valiant, A5e, Esper Genesis, Broken Weave, and others so, from that perspective, Tales of the Valiant is 5e. But I presume you're comparing it to either D&D 2014 or D&D 2024.
Full disclaimer, I have yet to play Tales of the Valiant and have only one session of D&D 2024 under my belt. Also a disclaimer, I wrote material for TOV's Monster Vault and upcoming Gamemaster's Guide.
Tales of the Valiant is high heroic fantasy. They fixed a lot of class stuff and I don't think they went as overboard as WOTC did with D&D 2024. However, they didn't really spend much time cleaning up spells so there's still issues with the various conjure spells, heroes feast, counterspell, and other spells D&D 2024 cleaned up.
They have their own version of weapon mastery but it has a limit on only being able to do them once per turn and omitting damage to do so. I prefer that limitation and cost, at least on paper.
Each class has only two subclasses compared to D&D 2024's four, so that limits it a bit, but I expect we'll see a bunch of new subclasses from Kobold Press.
The TOV Monster Vault is out as well and the monster design is fantastic. Easy to run at a table with a definite modern design of not burying a monster's CR in their spell listing. Much easier on the eye than the new D&D 2024 style.
It also has the best encounter building guidelines ever put down on paper... but I might be biased in that assessment.