Gyarados rate.

The crunch hits so hard! I have not gotten used dodging it yet :/ and they say DT is the best defensive quick move so that's an awesome set for defence! I don't attack with gyarados though :)

I'd love to have him, congrats. I wouldn't use him as an attacker, but I'd certainly power him up and stick him in gyms as a defender even with his weaknesses as a defender.

I wouldn't recommend using this set as an attacker, it doesn't really shine against anything in particular, and has the lowest cycle DPS of any of the Dragon Tail movesets, but it's a really good set for defense.

As far as the DT sets go on defense, Outrage is the best, followed closely by Crunch, with HP somewhat of a distant third -- but they're all quite good. In Gyarados' worst matchups, I.e. Jolteon and other electrics, Crunch seems to perform nearly as well as Outrage as it hits often. The raw numbers also show that it puts out more damage than Hydro Pump and you don't have to worry about fainting before being able to use a charge move.

Very good moveset, one that I would be happy with.