Crunch VS Stone Edge

For regular gyms crunch is certainly the better move.

I've been trying to decide the same thing. I maxed out my two best Tyranitars, and they just happened to have Stone Edge for one and Crunch for the other. I feel like anything I would use the stone edge one for, Golem does better, so it's more useful having them double dark, but I don't know if I want them both to be the same.

For you, however, if you only have one, I think I would go for Crunch. I mean, probably better if you can power up a 2nd one instead of TMing, but that's not always a simple solution, even with raids. For a while, every single Tyranitar I got either had Stone Edge or Fire Blast that TMed into Stone Edge, and it annoyed me that I just couldn't get any with Crunch. Once I finally did, though, it happened to be my 2nd best, so that worked out okay, just took a while.

Not unless you have a lot of charge TMs stashed away that you are willing to spend in case you need to cycle through Fire Blast a few times.

I think Crunch is more useful (both gym generalist and raid specialist), but I have 2 of eacht boosted to 30+, 3 unboosted with Crunch, and 1 unboosted with SE (all of them atleast with 89% iv and 15 atk), so never really bothered TM'ing any of them from one to the other. I also only have one proper Golem, so i use the SE ones a lot.

Imo, if you have the option to catch more don't change but otherwise do.

Leave one B/C and one B/SE. B/C is better for gym takedown IME and will be the best counter against Mewtwo and Mew.

Stone edge is better on: gyms ,pvp (someday could be a thing), dodging. Crunch is a must move to have if you planing to solo t3 raids (Gengar, Alakazam) and useful as a better moveset if you have trouble to gather enough people for T4, T5 raids, if not, bite/SE is fine. Both moves are good to have but serve different purposes. If you are desperate for a dark attacker and you can't have another T-tar with crunch then TM her to Crunch, if not bite/SE is fine. I would wait for gen 3 if i were you in case SE turns legacy.

at the moment crunch is better than SE however if niantic give ttar a rock type quick move and make SE legacy you will wish you kept at at SE. personally I TM it if its FB and otherwise keep t as it is