|From Google (not mine... yet)|
"I kinda get the comparison you're making between Assault and Shooty terminators, but I don't think you worked out the 'true' difference very accurately.
1st off, against vehicles, Thunderhammers offer no advantage over Powerfists. No more autostuns. Vs infantry, you reduce them to I1, but aside from mega-deff characters, you hit them with a thunderhammer, they should be dead. So this rule comes into play maybe 25% of the time. Therefore, for comparative purposes, pretty much the sole difference between Assault and Shooty Termies is having either a Stormbolter, and thus a shooting attack, or a Storm Shied, and thus an invulnerable save.
Quite clearly, on a points vs usability scale, the Storm Shield wins every time, Those 3++ saves being invaluble. However, now power weapons are nerfed, the need for an invunerable save on Terminators has reduced considerably.
For me, the main difference between Assault and Shooty Termies is that Shooty Termies can operate on there own and still be 100% effective. Assault termies need a land raider minimum, and generally they need an IC in there too. If we exclude the IC requirement, just the Raider more than Doubles the cost of the unit. Ok, you're not JUST getting a transport with a raider, but to use your termies effectively, that raider has to throw caution to the wind and get up nice and close, which means melta time.
Those points spent on the raider would get you, well, another unit of Terminators! Plus HQ upgrades for both. Lets not forget 'normal' terminators are still putting out 3 S8 AP2 attacks each on the charge. With an assault cannon, they’re also putting in 12 shots before the assault to boot. If you’re doubling your numbers by loosing the Land Raider, well the numbers just get silly.
I think the changes to Power Weapons and vehicles put Shooty Termies out front in 6th, for me anyway."
My reply was going to be a bit long for a comment (and I was hurting for content), so I figured I would do a full post to reply. He makes a lot of good points and admittedly, I was pretty torn between Tactical Terminators and TH/SS when I was writing up the list. However, I decided to stick with my 5th Edition staple for the following reasons:
Survivability--Yes, power weapons don't do anything to Terminator armor anymore, but a 3++ is still hard to pass up. And honestly, when I lose Terminators, it is to two things: massed saves and AP2 shooting--not power weapons. Both varieties die the same when rolling ones, but TH/SS Terminators last twice as long against AP2 shooting. As I mentioned before, I am expecting to see more and more AP2 in this edition due to reduced cover, the addition of hull points, the power weapon nerf, and AP2 offering a bonus on the vehicle damage table. If that turns out to be true, then the value of the 3++ saves will go up even more. Also, 3++ saves come in handy for a lot of other things including Psychic powers, MCs, Rending, etc.
Role--The survivability difference plays directly into how I intend to use my assault units. I try to use them as a direct counter to my opponent's nastiest unit(s), rather than a purely offensive force. There are a lot of Deathstars that simply cannot be killed by shooting before they hit my lines, and I need a way to dig them out. It's never fun when assaults finish in your assault phase and your opponent gets to charge again without getting shot, so it's nice to be able to send in a solid counter assault unit.
I prefer TH/SS Termies in this role because there is literally nothing they can't handle. MCs get leveled, PK Nobs either go smush (foot variety) or get tarpitted (Nob Bikers), Bonesword Warriors fall apart, Warscythes bounce off, and Walkers get turned into scrap. That is a unique role that regular Terminators just aren't as good at. While Tactical Terminators might seem more flexible because they can shoot, their shooting simply isn't powerful enough to offset their lack of survivability, especially when the extra 30 points of heavy weapons are factored in. Rather than having a unit that is solid in assault against some targets with mediocre shooting, I would much rather have an assault unit that can handle anything in the game.
"Speed"--One argument for Tactical Terminators is that they can impact the battle with shooting as they walk into position for assaults--eliminating the need for an LR. The idea is that those points can be put into additional Termies or other units. However, I think the LR provides a lot of utility on its own. I am a fan of the LR for its ability to put out consistent, high-quality shots while it is moving around. Also, it not only protects Termies from small arms fire (best way to kill both varieties), but also allows them to get across the battlefield faster (18" a turn now) and extends their assault range (potentially 24" with an average of ~19"). Having that additional threat range really helps one unit to protect a larger part of the gunline and can make an opponent more tentative about trying to get close to the shooty elements. A slogging unit is just too easy to avoid IMO, and I don't think buying additional bodies for the unit mitigates that issue at all. Also, a slogging unit really has no way to be aggressive unless it tries to deepstrike, while the LR can try to missile the Terminators into the middle of a gunline if needed.
Caveats: As I wrote this post and did some more reading about how vehicles and assaults work in this edition, I have become more and more torn about which choice is the best for my list. Unless it is FAQ'd, Assault Vehicle does NOT allow units to assault if their ride gets blown out from under them. While this isn't a huge deal with AV14 and 4 hull points, it is still something to consider. Also, slogging Terminators would allow Calgar to bring his AP2 Stormbolter and Orbital barrage to bear more often while they push forward. Also, dropping the LR does free up a significant amount of points to put into more shooty units. Removing it would allow me to field a TFC (more anti-infantry), upgrade the Dakka Pred to a Lascannon Pred, expand the MM AB squads to three each, and buy a shooty weapon for Tactical Termies. That is a lot of extra shooting...
At the end of the day, though, I like the overall flexibility and durability the TH/SS Termies and LR bring to the list. But I think it is more a style/personal preference thing than an effectiveness issue. And honestly, if I had my Space Hulk Termies actually painted along with the extra Bikes/TFC, I would throw them down in a heartbeat. I intend to test it out next Thursday, and I will post up a battle report or summary afterwards.