Is this build good for Fractals? (Firebrand)

[Mikau.6920]

Hey, I wonder if this build is good for Fractals, I want to know because there is a lot of gold needed to make the set:

http://gw2skills.net/editor/?vVAQNAnfbnsADdBjNDBGBDEEhF/BLLJUhyQ7V0O6I1KAUBqTA-jlhAQBQU9Hbu/oEEanAAAqPAAPBAQq8jUA8sGA-w

With this build I have "only" 97% of burn duration. Should I always have 100% burn duration?

Comparing with this build:

http://gw2skills.net/editor/?vVAQNAnfbnsADdBjNDBGBDEEhF/BzKAUBqTZJhKUGavi2RHpA-j1hAQBQU9iqpiCAeCAAUXAIV+FtTAoFwm7PKBJFAPrBA-w

I swaped the sigil of bursting for sigil of malice and a few Vipers for Sinister. Does 3% less burn actually matters? According the editor, I'll have 423 per second with burning on the first build (sigil of bursting) and the second one 413 (sigil of malice). That's 97% of the damage compared to the first one! Does that means in the end both of builds does the same DPS?

The positive about the first build (sigil of bursting) is it has more burst (even if only 3%) compared to the second one.

-edit-Is Signet of Wrath better than Mantra of Flame? I'm already using Mantra of Solace and Mantra of Potence because they are mandatory for the build, but I hate mantras.