I just made a PVP setup.. Figured I'd try out Infiltrator/Marksman/Riftstalker.
So far, I'm liking it. When people get close I have some melee ability and some good tankage. When people are far away I can nail them with my Marksman abilities. I've been taking out 20 or so people per Codex run at level 20... with most of them being in the high 20s, so I figure it's working out well enough.
I was using Bard/Ranger/Sab and it was pretty effective, but as I'm levelling and unlocking more souls, I'm moving more towards:
Bard/Riftstalker/Sab
Just because 0 pt pets can get taken down relatively quickly in PVP, and summoning them back takes a while.
Basically going full points in Bard, and then offensive specs in Riftstalker, and Sab is either 0 points just for snare bomb, or 5 points for added 15% dexterity.
I focus on cadence and Call of Fury AE spam, and following around friendly Fang holder, slowing any enemies approaching him, AE spamming them, and keeping my motifs up at all times.
At level 16 or 17, I was surprisingly able to do pretty well in all or most categories last night (just got Call of Fury last night, it's nothing special, but AE damage spam definitely helps in WF).
In one close match, I was the healing leader, and I was still in the top 4 or 5 for damage done, kills, killing blows, etc. I'm almost always in top 3 when it comes to Favor, even in matches where I don't feel like I'm doing that well.
It's a good PVP levelling spec at these levels since favor gain is pretty reliable, unless your team just absolutely sucks for a match.
I did try a Riftstalker-focused build with just 8 points in Bard for the basic cadence, and I was getting stomped. I wasn't high enough level to have all the awesome perks for RS, though, like the +crit chance after phasing, etc, and it was hard for me to stay in melee range of some characters for my RS finishers.
Next up is an assassin/riftstalker/bladedancer build, I think, but I'll probably want to get higher level first so I have more points to use.
The thing that annoys me most in pvp, is the frikkin pets hitting me while im trying to pick up the fang or cap a node, if you can get that and an instant cast spammable aoe you will deny the entire enemy team from achieving the goal.