Still think I'll be taking Sac in most pvp situations unless they buff demon survivability some- way too squishy atm. And honestly with the amount of CC that healers have these days, it's not like the pet is easy to keep connected for CS anyway.
As an aside about lock pet design direction - I'll add that I leveled my lock in vanilla without a pet (DemoSac:VW was the way to go back in the day - 3%hp/4sec was OP!). Before avoidance, we couldn't really have a pet out anyway a lot of the time. Even in TBC, I raided as Sac, or if I did raid as, say Aff, I would just keep the pet on passive to keep it alive as a Dark Pact/Fel Int buff bot. This bullshit of locks being a pet class really didn't even come into play in WoW until LK. There's certainly no class design history that mandates that we can;t have Sac as a valid gameplay option.