I would personally go with Dragon Pulse simply because it does much more damage. It's slower, yes, but since I usually use my charge moves after dodging the defender's, the extra animation doesn't matter (plus the extra damage from DP compensates for the few Dragon Breathes you could have used in the time difference). Dragon Claw is still a good hyper aggressive attack that allows you to bombard the defender with non stop dragon power, so I wouldn't be mad at getting either.
DB/DC vs. DB/DP Offense Dragonite
I'm having a dilemma if it's worth accumulating Dratini candies to power up my Dragonite with DB/DP move set.
Per gamepress website, its offense ranking is only B while per the moveset rankings based on weave damage made by Professor Kukui, its offense ranking is Number 2 or 99.50%, which approximates the Number 1 or 100% DB/HB move set. DB/DC is only Number 3 per Prof Kukui while it's rank A per gamepress.
Does this mean that Gamepress factors in your dodging capabilities and how you efficiently use your special attack while Prof Kukui's assumption is you just attack without dodging and when energy is filled up enough to cast DP, you cast it?
https://www.reddit.com/r/TheSilphRoad/comments/4vcobt/posthotfix_pokemon_go_full_moveset_rankings/ https://pokemongo.gamepress.gg/pokemon/149
Answers
Not only does Dragon Claw deal more damage, it's also ideal because it's such a fast charge move and with that you're able to fit in your dodges much more effectively. Dragon Claw is definitely stronger, I have no doubt about that.
Also I'd rather suggest you use the Qmike's spreadsheet instead of Kukui's. I believe that Gamepress rankings are also based on Qmike's spreadsheet.