Tried some PTR BGs last night. Here are my thoughts:
Marksman
Was worried about MM for PvP, but it was actually alright and even fun to play. Dumping focus with a cast time feels very odd initially. However you get used to it and I found the constant rhythm quite fun. I didn't feel I needed to play around standing still or managing Sniper Training either. MM hits like a truck regardless. Sniper Training feels like a bonus and not a requirement which I imagine was the intent for it in PvP. (Might feel more mandatory to keep it up in PvE).
I could imagine some synergistic rhythmic gameplay around Sniper Training, Focusing Shot, & Steady Focus and setting up some weak auras to keep track of the combined buff.
What I did miss was any dots and I thought that Chim Shot felt so weak as to be borderline redundant compared to just using Aimed.
Lack of CC felt bad but thats the same for everyone and traps now feel really great with their instant arms.
Had some great Casual BG runs with constantly being at or near top of HKs, Damage Done and Honor Earned etc etc.
Obviously L90 Casual PTR BGs isn't L100 2500 RBGs but Marks *feels* fine for BG PvP from a purely mechanical/fun PoV.
Survival
Ugh. I had some hopes for some new era of SV in PvP but it just feels so weak. Explosive shot hits for so little and I found it impossible to kill anything. Even if LnL multiprocs it still amounts to not a lot. Playstyle is similar to live so this feels like purely a numbers thing. I felt emancipated.
I'm going to give BM a try tonight but it appears to be very similar in playstyle to live.