like title say wich would be better? i hear scoundrel dps is bad for pvp!

If you are looking to play ranked warzones, the assassin dps isn't really any better for it. There will be people on both sides who tell you the pros and cons, and yes we do have pros. If you want to get into a team of ranked with non friends, you could go tank shadow, or hybrid shadow, as those are both fine. If you want to stomp around in regular warzones, both do extremely well at that, I can even top the charts on damage against smashers as a scrapper scoundrel