Which condi builds are the best at OpenWorld/Fractals and PvP?

Hi. Burn Guardian builds used to be fun and easy to play; did use some variants (burn on block, burn burst...) in the past but I'm not sure which current specs are better/more effective in those game modes:

Open World/Fractals: which condition guardian builds are better? Core, Firebrand... Do DH spec provides useful things gainst the AI? How do these builds perform in that environment compared to cookie cutter power DH builds? How good/bad is mobility and survability?

Which is the strongest PvP/roaming condi based Guardian build at the moment? Is better going full condi or hybrid builds provide more balanced matchups?

On Snowcrows, there is a guide for the strongest condi build. Personally I run a full Griever version. There's a lot of minor tweaks that can be made, and switching between viper, griever, and sinister pieces only create the most minute changes, but the general gist of that build is pretty good. There's the pure damage version, but there's also a quickness version for giving the team quickness.

Condi firebrand is one of the best condi builds in the game. The mobility is low, but in PVE you really don't need mobility. They survive fine.

For PVP/WvW... I have no idea. There's a couple of threads on this forum about it, but I'm not sure if they're anything other than meme builds.