Just went through the list and it seems Tau have 11 Weapons that are Ap3 or better. If I'm not mistaken the old dex had 7 weapons of Ap3 or better.
So how much can I buy your Tau stuff for? I need a few Piranha if you have em, I prefer unbuilt and still in the box. I'll give you £5 for each Piranha.
We still dont know for sure how many of these you could potentially put in a list but my guess it's allot more than we could we the 4E dex. The Kroot Sniper rifle gives you the chance to take 120 sniper rifles in an army if you want to.
Ion Accelerator S7, Ap2 Heavy 3
Railgun S10, Ap1 Heavy 1
Fusion Blaster S8, Ap1 Assault 1, Fusion (hmm, the hell does that mean? Melta rule with a Tau name?)
Neutron Blaster S5, Ap3 Assault 1
Ion Cannon S7, Ap3 Heavy 3
Plasma Rife S6, Ap2 Rapid Fire
Seeker Missile S8, Ap3 Heavy 1, Single Use
Rail Rifle S6 Ap1 Rapid Fire
Heavy Rail Rifle S8 Ap1 Heavy 1
Long-Range Pulse Rifle SX, Ap5, Sniper (for Rending), Rapid Fire
Kroot Rifle with Precision ammo, SX, Ap6, Sniper, Heavy 1
The point is: they all suck against MEQ.
ALL OF THEM.
Neutron blasters: Carried by the most overcosted and terrible unit in the game, from any race.
Ion Cannon: About 300% as expensive as it should be, competes with Railgun.
Railgun: If you're using this on anything but tanks or huge hordes (submunitions) you're doing it wrong.
Rail Rifle: overcosted, 1 shot won't help kill marines, pathfinders only which means nobody will cash in a crucial markerlight for one. Don't even mention Sniper drone teams, suck suck SUCKAGE.
Fusion blaster: not even an option for MEQ hunting.
Seeker Missile: Now you're grasping for straws. Most people don't even take these anymore, not even for shooting vehicles.
Plasma Rifle: Overcosted, but is still the best (and ONLY) option. You CAN'T however field enough of them. Ever.
Against Marines, Tau are going to be doomed unless there's no new high rate of fire AP3 weaponry that doesn't cost an ocean of bananas. Or at least a 5-point decrease on Vespid.