In some ways, it got a little less balanced. Tau infantry is much closer to horde prices and that's dope. They weren't great, but now you can field a lot of them, and some of the sept traits really help out with that.
On the other hand, you had situational abilities like the Ethereal's buff bubble, granting an optional bonus on each turn. It was nice, but situational, and Ethereals were much less useful in combat than, say, a Space Marine captain. However, ethereals went up in cost, while each of their aura abilities can only affect units once per battle now, making them more expensive and even less useful.
A unit of two Tau drones, taken as wargear, still confer full victory points on death, which means taking fluffy lists with drone support (not drone spam) makes almost every unit in the codex worth twice as many victory points for killing.
Three other factions get a better army-wide stealth trait, and two others get a better army-wide cover bonus.
The codex has a unique keyword, JET PACK, in both the index and codex that costs extra points to optionally confer on some HQs, but that still has zero effect: It doesn't trigger stratagems, wargear, powers, or even transport limitations. Does literally nothing.
Tau's elite anti-tank options do less per point, per wound, and per model than horde tank options.
The guy who wrote the codex admitted to not playing or understanding the army.
No matter how many riptides got shoved up your ass last edition, Tau has legitimate reasons to feel a little over nerfed this edition.