I am playing the Tales of the Valiant Alpha release, and it feels like a solid 5E base game. This could easily replace the 5E Player's Handbook for me and serve as a competent 5E rulebook. Being an OSR fan, I don't want to shop with Wizards anymore, and my trust in them will only change once the leadership teams of both Wizards and Hasbro change.
This is fair; it doesn't trash the 5E game or fans but holds people accountable. This also doesn't create a situation where trashing 5E would hurt 3rd party developers, I support 5E alternatives and a bunch of great companies can keep their employees, writers, and artists paid.
I would like to see more direction from Kobold Press going forward, like their product roadmap. Will they be presenting expanded classes? Their back catalog is compatible, so books like Deep Magic are already there as expansion content. A lot has to do with the success of ToV, and they will straddle the fence with 5E/6E/ToV compatible books. This way, any book they publish will be a winner.
Want to play Midgard with 6E? It works! Sticking with 5E and want to buy Tome of Beasts? It works! Want to use Deep Magic with ToV? It works! Of course, they want you buying ToV, but this gives the company a fallback position in case Wizards tries something else.
What do I want to see? For ToV to move forward as a game, take the Pathfinder 1e route with "Advanced Players Guides" and expand classes and character options in their own style to work the best with their own ruleset. I would love to see them become their own game.
Will ToV - on release - go far beyond what 5E gives us? I doubt it. They will fix the game's imbalances and exploits and tighten the math. They may change a few subsystems (like inspiration), and you could quickly drop their luck system and use inspiration instead. But ToV doesn't need to be other than a balanced and repackaged 5E on launch.
And they will face the same pushback as Level Up: Advanced 5E did, with so many voices saying, "It is just another version of 5E!"
Well, that is what it is supposed to be.
And really, that is all I want this game to be - at the start.
The more exciting things will be to come with their first expansions for the game and the direction they take things in. But this is a new beginning, and one people can get on the bus with. The hobby needs that for those who still want accountability and others who want to get in with a brand-new starting book.
If I want a new "total conversion" 5E game that takes the game in new directions? Then Advanced 5E is still my choice. I don't expect ToV to support robust (and entirely new) exploration and social mechanics. A5E brings back D&D 4E's "battle leader" class and emphasizes environmental hazards as a part of the initiative track (and exploration challenges).
This is 5E blended with OSR concepts, and that lets them rebuild the ranger class to be more than a flavored combat class with a few "before the dungeon" abilities that are rarely used during play. The ranger is essential to survival in A5E, and they are to the overland game what rogues are to the stealth game. They are masters of exploration and irreplaceable in a party.
Caster can find rare versions of spells?
They double up the background abilities for the social game and include a bunch of fun-specific social bonuses to use. Where ToV focuses on a few, A5E goes deep, and you have a list of fun abilities that apply to roleplay and social encounters. Old 5E looks like a simple B/X combat game in comparison, and the characters feel like bland collections of combat powers.
People that say, "They should have just built this for 5E," don't understand A5E. They needed a complete rebuild like a total conversion mod for Skyrim usually ends up needing a complete rebuild to support the features they want to add. When you are that deep in the weeds, you get to a point where you say, "We have it all ripped out, let's fix everything!"
Is A5E still compatible with 5E? Yes, they are closer than ToV (in some ways) since they maintain the inspiration mechanic. The math behind classes and damage are cleaned up and tightened considerably, and many exploits have been addressed. But 5E content ports right in, just like any OSR to OSR B/X style content typically does.
Both ToV and A5E clean up math and exploits.
ToV will likely be a closer to the metal version of 5E with a few changes.
A5E is like a total conversion mod turning 5E into an OSR-style experience.