You now have two flavors of 88's; the "shoot so many missiles I feel like a spaceahip" High-Yield Missile pods or the "too depressed thinking about my smaller gun" Heavy Rail Rifle. Both weapons are very powerful and each can play a significant role in any Shas'O's cadre. However some folks would argue that more missiles is redundant and the "boom stick" is ineffective, so let us journey down a little track of statistical paradise and probabaility utopia.
Boom Sticks
Just in case you don't get the joke; these guns look a whole lot like sticks and they make things go boom...Boom Sticks....
Heavy Rail Rifles are a weapon that many tau players dislike because much of us are stuck in the old days of 4th, but I promise you that they are still a force to reckon with and that they still have the skills required to make you want to say "boom, baby, boom."
A few things that have really hurt this loadout is the loss of the Advanced Stabilism System and of course the drop in strength and range of the gun. However they have quite a few new good things going for them now; Support Shas'O's are eztremely deadly when attached to this type of squad, they can take up to 6 shield drones, they can take seekers and they now have a whole plethora of magnificent aupport systems to choose from.
Finally, and maybe most important, is the fact that Boom stick 88's excel at destroying Monstrous Creatures. Toss in the Shas'O with his good ole Puretide chip and once again you have a huge mess in front of you that used to be a MC. Now that every codex seems to be getting these juggernaut horrors added in their lists (and almost every one takes them), you may really want to consider these guys. This is literally their ideal niche while Hammerheads focus on heavy armor and Riptides take out elite infantry and occasionally MCs, you need some more reliable "Monster Fighters".
Is that a Skyray?
Funny enough, no it's not a Skyray, but a three man squad with High-yield Missile pods, seeker missiles and Missile drones (could you use the word "missile" anymore than that?). Yet another fun way to field XV88's and a highly effective one when fighting horde armies or massive amounts of light armor.
If you really don't like flyers and don't want to spend points on Boom Sticks (because you find them "worthless") and don't want to buy Velocity trackers, then don't worry! Missile 88's teamed up with some lucky Markerlight hits will tear through flyers like a hot knife cuts through butter (although it doesn't tear). Of course you won't see too many pens compared to the Boom sticks or explosions when you do penetrate, but you sure to the Greater Good can glance the thing to death!
Just because they are AP4, don't necessarily toss them aside. They have a rather high strength, high rate of fire and great range compared to most other shooting armies (Eldar and Necrons) so they can deal some damage, but your opponent may absorb the shots with his army. However; if you play against low toughness characters, you can score multiple Instant Deaths with them! Equip them with Advanced Targeting systems and hope for some 6's out of your 3 man, 12 shot squad. Focus your fire on the low toughness leaders (Eldar, Dark Eldar, Imps) and they've lost their leader support.
My only problem with this choice is the fact that suits come with Missile pods, can take two per suit and still retain their higher sense of mobility. I feel as though Suits fill this niche much better, but then again one could argue that Boom Sticks are obsolete for the same reasons (fusion blasters on Piranhas, Suits, or Stealthsuits).