I played a online session last night with my half-elf (drow blooded) slayer (revised) character (char sheet). DM ruled I could do favored class for 1/6 slayer talent. If not I just would have used a feat instead of combat trick to get power attack at 5th level and not have dazzling display.
I only got one battle in, but must say was happy in that one battle. We had a warpriest, brawler and arcanist also. I of course forgot to activate Favored Target during stealth before combat. Was in a 10 foot wide corridor and came upon 2 hyenas (advanced ones probably), 2 gnolls with melee weapon (ranger classes I believe) and 2 human slavers with whips and (not sure what classes they could of had).
I did some good amount of ranged damage with some good rolling, then again I had +11/+6 on ranged with deadly aim. First attack was the only low roll, but hit due to target flat-footed.
Round 1 (surprise on enemy) - 5 foot stepped and got a ranged sneak attack off for 17 damage on hyena. Round 2 (full attack with haste) - hit a gnoll for 43 damage and if I had confirmed a crit or had favored target on it, it would have gone down. Round 3 (full attack with haste) - hit the same gnoll with the first arrow (haste with confirmed crit and manyshot) and that gnoll is extremely dead. The other 3 arrows hit one of the slavers and takes him down to half HP at least.
Round 4 - one slaver left and surrenders to us.
I am liking the slayer class. I think they can hold there own. This is the combat rogue I always wanted without multiclassing. Some talents tied to favored target would be good, but I was happy so far. At 7th level with shatter defenses and a warpriest that also has Cornugon Smash (which I didn't know he had until last night's game session), I think I will be raining death next level with sneak attack (ranged or melee) assuming targets are shaken either by me or the warpiest.
The other 3 classes looked ok from what I saw. Will not have time to give a further review since the playtest will end before we play again.
Thanks for posting your playtest feedback! :)