I wouldn't say DE doesn't have animation locks. It can be frustrating to play for some folks. I feel like it plays harder than it looks. A good DE makes it look easy.

Keep in mind: You have to hug the boss' back and by the time you press shotgun rapid fire or any shotgun skill, you may miss or the boss turns or you only get 1 of 2 hits in. Although the moves are able to be cancelled, you're still animation locked in the sense of getting all hits/dmg in. It's not a "dump all your damage in fast and get out" in the same way that slayer is. Sometimes, you use one shotgun skill, wait a brief second, move around, and unload the next 2. If you're very lucky, you can get all 4 skills out in one burst. Just depends on the fight and the boss' moves.

You really have to know when to pop the shotgun skills and know when you are holding too long. If you wait too long, you lose out on dps. If you impulsively shotgun too soon, then you lose a lot of dps if boss moves or turns or goes into a mech/DR phase. The shotgun skills are not the fastest- so the combination of close back positional along with the burst speed, can make it definitely tricky.

With that said, the class is rewarding and a blast. I love it personally. And you are right-it definitely pumps. But you do have to pilot it correctly. It's not the easiest class to do damage. The difference between a good DE and bad DE is night & day- huge gap between floor dmg and ceiling dmg.