DeviousQuail
Hero
Both are good but I've used Xanathar's a lot for tools, crafting, and downtime stuff so i voted for that one. If it were just class/subclass stuff I'd give the edge Tasha's.
Well, I imagine most of those will be consumables, but yeah, it’s definitely a lot. I agree that it’s useful to know the design assumptions even (I might even say especially) if you want to break from those assumptions.At level 20, a "party" however many that might be is expected to have 100 magic items. Say 20 items each. Heh, this is crazy talk for my campaigns. I max at about 8 to 10 body slots. But it is useful for a DM to have a sense of what the designers are thinking. So DMs can confidently pick and choose which items to assign depending on the narrative circumstance.
That's the way it looks from my perspectiveMaybe, Tashas is slightly more useful for a player to fix certain classes and customize the character concept, and Xanathars is slightly more useful for a DM to adjudicate tools, crafting, and magic items.