For casters the legendary meta gem with the old hardmode raiding helmet is really good however. For rogues the legendary meta gem is not all that viable for PvP in my opinion.
i believe crit will be the way to go next patch for sub, so since we lost the free 60% crit on ambush and 30% crit on backstab from the old cata talents, Id say crit could become more valuable than pvp power since backstab/ambush should once again be our main source of burst damage and it also means more combo pts from HaT and so easier time keeping up snd, recup and rupture(rupture crit tick also proc HaT so its still worth doing even if u got the hemo glyph and your target isnt plate). So imo the crit pvp trinket/battlemaster could more valuable than the agility on-use and maybe even the proc trinket if you look at it from an utility point of view and more reliable burst instead of just raw damage on some pve spreadsheet.
dear god i hope legendary meta gem is not gonna be a thing