Good Players adapt, bad players complain about everything without looking at the big picture.
Cannot keep the enemy controlled? Stop drinking the kool-aid, the 1.5s knockdown now fills the resolve to half, so after the 1.5s knock down you can chain in a debilitate, stun locking them for 5.5 seconds.
Acid Blade was not "destroyed", the damage has stayed the same, yes the 20% reduction in armor pen was a bit unexpected, but 15s of 30% armor penetration on a 1.5s CD is still a pretty strong ability.
If you're trying to burst someone down in the middle of group pvp, you're doing something wrong, pvp is still pretty group-centric so you try to kill one person with his friends nearby, and you don't have any backup, they are going to beat your face in.
If you really think concealment is so broken, there are 2 other specs to experiment with. Ops are very capable healers, maybe not as powerful as sorcs but a great deal more mobile imo with some good burst healing. Lethality is also a pretty strong spec, and if you spec hybric med/lethality, you mitigate the TA issues that lethality normally runs into and you get alot more durability.
Yes their damage went down, but it's not to a point to get overly concerned about. Any concealment op that's worth his salt is taking the changes in stride, adapting their playstyle to the changes and are still achieving good results in PVP. You just can't do "LOLOLOL AB LOLOL HS LOLOL BACKSTAB LOLOL FREE VALOR" You actually need to play smarter now.
So go ahead and "unsubscribe", you'll be back.
TL;DR - Ops are still fine. Quit crying that you're no longer FOTM