T100 power level still?

Duriel is just for drops, it could help someone gear up so they can level themselves as it drops 925 gear only and you could get weapons to help yourself.
But nah, fastest leveling is nightmare dungeons that are 10+ your current level for max bonus exp.

Appreciate it. Still only a few builds are viable again right? I played sorc and nothing is godly besides blizzard.

Depends what you enjoy doing, if you enjoy endgame content, pushing AOZ dungeons, speedfarming, etc.

Here is a tier list for basic end game content, max rolls website has quite a few different tier lists you can choose from based on the content you enjoy

https://maxroll.gg/d4/tierlists/endgame-tier-list

Not bad.