I've reached 2.2k as both sub and muti on different servers but it was mostly in full gear, now that I actually have to gear I'm a bit unsure what spec to pick.
Current daggers are 2xNamlak's Supernumerary Sticker and I only have wrath bracers.
If I remember correctly muti did better in less gear damage-wise but struggled with survivability. I'm thinking of playing sub though but don't know how it will go with less gear, I can set damage up fine but will I do enough to actually get kills?
Under normal circumstances, Envenom spec (44/2/25) will scale a lot better without gear but that doesn't mean you'll be MORE successful as this spec than you would be as subtlety. A lot of the factors depend on what you're planning on running in arenas. If you want to run with a healer, I would say you'd probably have more success as Envenom with your gear. If you want to run with a Shadow Priest or Mage, I would stick with a deep Subtlety spec.
In my personal opinion, Subtlety is still better than than Envenom against targets with lower armor even if your gear isn't BIS. However, Subtlety doesn't perform that well against plates until you have somewhere around 30% armor penetration. To hit this number without running a super low resilience build (I don't suggest doing a low resilience build obviously), you basically have to use Deathbringer's Will.
You'll be able to set up damage fine playing Subtlety against just about anything except Warriors, Paladins, and sometimes Death Knights. In these situations, you'll have to rely on your partner's damage to a certain extent. You'll still do meaningful damage with Shadow Dance as Subtlety, but I doubt you'll solo a plate until you have significant armor pen.
But with that being said, just play what you enjoy playing!