Dark Tyranitar as a gym attacker
How useful is Dark Tyranitar as a gym attacker? Against the Normal-type tanks, it is much slower than Machamp and equally weak to their Fairy-type moves (despite resisting all their fast moves). Gardevoir and Metagross have secondary typings (with STAB moves) that punish Tyranitar, while Exeggutor and Slowbro are not that common here (ironically, they were very common under the old system). Will Gen IV introduce good Psychic-type and Ghost-type defenders?
Answers
Not really useful. The best psychic-type defender is Gardevoir whose fairy type makes it neutral to dark and B/C Tyranitar's neutral damage isn't great by comparison to other top-of-type attackers. I sometimes bring B/C Ttar because of its 3-bar charge move for clearing low motivation gyms but that's it.
If the DPS was adequate, Tyranitar being weak to the defender's moves would be a non-issue, it's incredibly tanky.
Gen 4 will introduce at least Drifblim, which might be used as a Machamp wall due to its triple resistance. It's not tanky enough to pose a problem for generalists and people will likely pack a flying-counter anyway due to Togekiss.
I've always found it useful but thats because where I am Its almost always foggy in the morning so my Dark tyranitar makes quick work of most things, plus its at the top of my CP sort so it always an easy find. But outside of that, if you dont have that foggy boost and low motivation on gyms, it isnt that good for clearing out