PVP wise, I had much much greater success with a hunter over my Titan (like 1:1 k/d versus .4:1) golden gun is great to pop when you're about to head into a room with multiple defenders on a flag, way easier to get off two kills versus having to run into melee range as a Titan when they're likely to have you dead before you get off your super. And double jump just seems a lot more user friendly that the Titan rocket boost, less likely to keep you floating in mid air, and still lets you reach the little alcoves and shit where you sometimes need to get.
And yea, throwing knife is obviously way better than the titan's melee, maybe not as good as lowering your grenade cooldown, but still pretty nice.
Pulse rifles seem fairly worthless in PVP, they work great in PVE, because doing the strike with a scout rifle fucking sucks on your trigger finger by the time you've drained 300+ rounds against each boss. But a scout rifle or auto seem to be the only way to go for PVP. Even "if" all three shots hit in PVP, it basically only does as much damage as the scouts one hit, and headshots are way more likely to hit on the scout.
Hand cannons, I haven't really tried, they just seemed really underpowered in PVE, haven't tested it in PVP, but I'd expect it to be similar, might as well use fusion or shotty if you're regularly shooting in tight quarters.
Shotguns and fusion rifles seem fairly balanced, I think fusion is more likely to one shot from longer range, but the buildup is harsher, sniper seems useless outside of the moon map.