Yep Viper is very fun for me as well and been the type of Fast attacking Assassin like job I've been looking for as my Main since 2.0 era.
However, I still feel they could have organized the Burst/Trance Mode better when activating Reawakening.
It feels too scattered between 4 skills that are meant to be for two separate combo chains when not using Trance mode. Not to mention once level 100, it adds the additional skills for weaving between each attack.
They handle this issue well with Gunbreaker having the burst skill Mode set as a single skill with continuation for weaving. They did not need to scatter Trance mode skills between 4 separate skills that start out completely separate from each other.