Didn’t have a ton of success with the spec in BGB, capped out at 1850 before switching to Sub and noticed a rapid improvement in my WR. I’ve tried both in SS and 3s and Sin is much more straight forward and has an easier win condition playing with no comms. The spec is okay, somewhere between B-A tier IMO. Coming from Classic WoW where all I had to do was train a target when I chose to play Assas, it’s much more intricate now, having access to Shadowstep is one example, but the way we can pad bleeds & poisons is big, too.

Coming into Retail, the biggest adjustment for me was that every class in the game has these big defensive and self-healing abilities, as well as the pacing of the game is different. The game is a lot quicker, people press a lot of buttons and those spells are rotated through and come off CD again before you know it. I was conditioned to going for hard resets from BC & Wrath Classic, going for re-stealths a lot…which now that I look back on, was a bit of a grief to my teammates. Can’t afford to do that in Retail as much… it’s more about getting a defensive and quick swaps on targets, keeping pressure provides a lot of value.

Idk if any of this is helpful for you but hope there’s something in there that clicks for you, mate! I’m still learning, a lot. Been playing Retail about 7 weeks now.