First read these
Armies in 5th articles by myself and then
this codex review by AbusePuppy. My articles a more focused on the army as a cohesive whole in a competitive 5th environment whilst Puppy's are a unit by unit breakdown in a more relaxed environment.
I have to disagree there to be honest. Our best anti-mech units are subject to psychic tests and at 18" range this means they will be in range of runic weapons/psychic hoods always. This really reduces the chances of ever getting that much needed pen on those evasive landraiders. In a competitive 1500 pts tournament like Throne of Skulls all SW lists have jaws of the world wolf, murderous hurricane and meeting one of these lists means the nid player needs to pack up and go home.
Tyranid anti-tank is a lot different from other armies. Whilst HG & Zoans are brilliant at armor popping (I've always given the nod to HG), the rest of the Tyranid force is about stopping your opponent from shooting/moving with his mech until your MC statlines bang away at rear armor. Throne of Skulls is anything but competitive sorry. Jervis failed massively with that one.
Nullifying 50% of our psyhic attacks whilst safely firing his own sick-ass psychic powers out of a landraider where he is safe from shadows in the warp means that Tervigons and T-fexes are going to bite the dust 66% of the time from a 100 point base-cost model. Any landraider heavy list also gives us major problems too. There is no counter to it and I dont like the idea of spending 160-220 points on an all-or-nothing suicide zoanthrope unit that will only get to use their pyschic power 50% of the time. Thats not including passing the Ld test in the first instance or making the 3+ roll necessary to hit.
Firing out of a LR? Nope

. Jaws is a pain versus nids but doesn't fit in a balanced army. If I get screwed over by it I'm happy to go home knowing if he ever comes up against a balanced list his utility spell is crap (or if it's his main spell...wow). LL, Tempest, Hurrican and storm caller are all much better powers than Jaws. Against an LR list (if @ 1500...well it loses cause it has no support) you take away it's support which you do have the firepower for. Whilst T-Fexes aren't the most reliable at taking them down, once their support is gone (which is the primary tactic against LR lists normally) or their cargo is unloaded you're okay.
I have played really mech heavy lists which lets face it most tournament players use now and each time I have been frustrated by the Tyranids serious lack of punch in that department.
3 HG squads = 3 tanks suppressed. 3 T-fexes = 3 tanks suppressed. 2 Harpy/Tyrant = 2 tanks suppressed. That's 9 tanks not shooting/moving/dead. Tyranid shooting isn't about popping tanks, it's about stopping tanks. Whilst HG do a pretty good job of popping lower AV, T-Fexes/Harpies will quite reliably stop a tank from at least shooting. To stop a Tyranid army shooting you have to kill it. My Tyranids have had no problems with mech and the worst matchup for them is against LR. All of those games I've been able to strip away their support and swarm the Terminators.
Nids can be tailored to beat anyone I agree and if playing for fun you can beat anyone with their codex. But their all-comer list just isnt too strong to be fair and its just these sort of rules that force a whole new list to be written...
Balanced competitive lists FTW.