I had a blast yesterday playtesting a 15th level warlock vigilante, Mariner Luna, styled after the iconic Sailor Moon. Here's how the experience was for me.
Playtest Basics:
-15th level homebrewed scenario
-Party (besides me) consisted of a cleric, an unchained monk, and an arcanist.
-Stats were created through 25 point buy and automatic bonus progression was used for items (with metamagic rods bought with the remaining wealth)
-The goal of the adventure was to enter a city sewers and take out a necromancer camped out there (along with his undead monstrosities)
Playtest Rundown:
I started the adventure in social persona (Bunny). The bonuses to social skills were nice to have, but they weren't game changing. Once we entered the sewers, I changed into vigilante persona and didn't change back again for the rest of the adventure
We avoided one fight entirely by stealthing around it, and then ambushed the next encounter (a group of undead, not sure what exactly though, the cleric didn't bother to identify and didn't through the whole adventure to my mild irritation) creating a situation where it was pretty one sided. I used mystic bolts (Moon Tiara Action) all encounter and found them to be quite effective.
The next encounter was less one sided. More undead made it so I couldn't use my startling/frightening appearance at all. I played more of a support role this time, casting haste round one and Greater Invisibility on the arcanist round two, then mystic bolting for the rest of the fight.
The boss encounter we couldn't stealth the boss encounter, as he knew we were coming by that point and put himself in a position where it would be difficult (if at all possible) to be snuck-up upon. The fight took place in a large room and the necromancer had some sort of souped-up flesh golem with him. The first round of combat I cast greater invisibility, the next round was quickened dazing fireball on the necromancer via spell perfection and a metamagic rod, and then full round mystic bolt attack. We focused the necromancer first as only he had the true sight to see invisible me, and dazing him made it easier. I mystic bolted the rest of combat at the golem.
Closing Thoughts:
-Arcane Training eats up a LOT of talents. It was so hard to choose which ones to go with because I had so few.
-I relied on mystic bolts to carry me through fights because of my small amount of spells per day. I don't know what I would have done otherwise
-I'm worried about what use I would get out of a social identity in a long running campiagn? I felt no compulsion what so ever to switch back out of vigilante mode, even in social situations all adventure. There was just no need. As an adventurer, it doesn't really make sense.
-That being said, I got a big kick out of doing the transformation between personas in front of the party (I did a blatant SM rip off transformation/speech)
-I output decent damage even though I wasn't really specced for it thanks to mystic bolts, a nice bonus.
-Overall, I had a lot of fun but the class definitely needs some tinkering on the identities bit, and I would advocate reworking the talents for warlocks so they get a few more that aren't something that should be their basic class feature.