I've had the weekend to go over the new Tau codex a few times, and while I don't have my brain wrapped around all of the changes and new toys yet, I'm definitely liking what I'm seeing so far. While it's a similar army to what we had before, it's definitely been altered enough to change up our game. Some of my initial impressions:
- HQ Flexibility. After years of having 1+ Crisis Suit Commanders and no real reason to take Ethereals, having multiple viable options in the HQ slot is a breath of fresh air. First of all, Ethereals actually bring useful buffs to the table without being a massive liability. Aun'Va does it even better, and for just under half of his original price - he's actually worth looking at for an HQ slot. The Cadre Fireblade is also a good inexpensive HQ option, and works very well with the massed fire tactics that are obviously the intent for Tau. Farsight no longer limits your army builds. Shadowsun can actually join other units (and gets especially safe in Stealth Suit units). Aun'Shi is back, even if he's a bit of an odd duck with his melee talents. I particularly like Darkstrider, who's going to be very nasty in concert with some of the toys Pathfinders can bring with them. Beyond the actual HQ choices, the Warlord Trait table is fantastic; it's nigh impossible to get a trait that can't benefit you in one way - and being able to re-roll unusable traits is awesome. They could stand to errata some of that into the BRB trait tables.
- Supporting Fire. Overwatch and improved Rapid Fire weapons were nice gifts to the Tau, and this new army rule gives us the hat trick for anti-assault shooting. No unit should ever be running solo when assaulters are on the table; being able to put forth a wall of pulse rifle death is too important to go it alone. The fact that markerlights are usable on Overwatch makes Pathfinders and other markerlight sources even more important in this army. Speaking of markerlights...
- Revised Markerlights. The new, cleaned up markerlight rules are great. At their heart, they pretty much do what they did before, but the clarifications and updates make it much clearer. No, your opponent can't try to save against them. The rules for Seeker Missiles are much more clear (thanks, Ignores Cover USR!). Removing cover saves is pretty much the same as before (given that default cover is 5+, it's the same as using 2 tokens in the previous rules). We lost the pinning bonus, but so few armies are vulnerable to pinning that it doesn't really matter. More importantly, being able to use markerlights in Overwatch and on Snap Shots lets us do things like let the new Pathfinder weapons move and still shoot at a decent BS, or let a Hammerhead move 12" and fire like it was still, or try to take on Flyers if our AA weapons aren't available. There's also just more and better options for getting markerlights. Pathfinders no longer have to pay the Devilfish tax. Marker Drones can be taken in squads on their own (or with a Commander with a drone controller for BS5 markerlight shenanigans). Also, no more limitations on who can use the tokens. Your Kroot can now snipe to their hearts' content and use your little red dots to do it.
- Shift in Kroot's Role. The Kroot are no longer our assault unit. They were never a great one, but now they're not equipped for hunting with blades. Instead, they're hunting with guns. Being able to get 7-point Infiltrating snipers isn't a bad thing. They still make passable bubble-wrap as well. Sure, they're likely only a speed bump, but that's all they ever were in that role. They buy you another round of shooting before the target gets to your line. They're definitely not must-haves, but it's worth trying them out in their new role.
- Best AA Codex Yet? Anti-aircraft fire is available in more varieties in this book than I think I've seen in any other codex. Missile Broadsides with velocity trackers. Riptides with VTs and early warning overrides. Sky Rays (finally!). Any other decent-strength weapon with enough markerlight shots. There's no real reason to take an Aegis Defense Line with this army, because you have more and better options for handling flyers. The weakest anti-flyer option in the book is, oddly enough, our own flyers, although they still have seeker missiles available (which can now be fired without markerlight hits, but are much better with them). The codex paints the new flyers as anti-infantry gunships, though, and I have to agree; that's what they're best at, even if they are horribly fragile.
- Cheaper Everything. Cheaper Fire Warriors. Cheaper Pathfinders. Free photon grenades. Cheaper Crisis Suits. Cheaper plasma rifles. Much cheaper Piranhas and Hammerheads. There's been a general price drop across most of the units from the previous codex, and while it's not quite as major as the drop in, say, Daemon Troops, it's still noticeable. At 1500 points, you're probably looking at around a 70-100 point difference between the same list made with the old codex and the new. That gives you the flexibility to do things like add an Ethereal, or replace a Crisis Suit squad with a Riptide, or add another unit of Pathfinders (and you'll get even more points if you drop the Devilfish that you don't have to take). Your old list will still work, more or less, but you'll have a bit more room to expand it. In fact, the only thing that didn't really come down in price much was the Devilfish, which is even less worth taking than it was before.
This just scratches the surface of what's in this book, but it should give you a good idea of what's available and in what direction the army is intended to go. I was excited when I found out that my Tau were getting updated. I think what we got was definitely worth the wait.