Mainly tank in PVP and do some group content, Trying to decide Vang or Guardian. Which has the smoother play style atm to help me get back into the game?

I haven't played the Guardian much since the KotET dropped, only through level 12ish, so I can't comment very well on how it plays. I've been enjoying my new Vanguard though (also tank). The biggest difference at first is that the Guardian gets Force Leap at level 1, if I'm right, meanwhile the Vanguard doesn't get Storm until 59, which makes things difficult. Harpoon, the Vanguard's super high threat pulling move comes at level 22, but it doesn't actually pull most bosses to you though because of movement impairing immuntiy.

 

They both have had their channeled attacks, Blade Barrage and Ion Wave/Ion Storm changed to be instant as well, so you don't have to awkwardly stand still in the middle of the fight. Less damage, but the mobility helps, especially in PvP.