In terms of raw dps, the weapons are actually closer to each other than one would think, but depending on the state of the game it might vary. Currently on JP, as far as i know Dsaber pulls ahead in dps, closely followed by knuckles and last would be twin daggers. However TD's have the advantages that they have access to very versatile aerial combat and there are some cases where neither knuckles nor dsaber can reliably reach.
I also heavily favor TD gameplay, but i do admit that in many cases the other two weapons are just the better choice. TD's profit from the fact that they stick to most weakpoints easily and get 100% "uptime" as you would call it, especially for beginners this is hard to replicate if you have to use knuckles or Dsaber in the air. I'd definitely recommend playing all 3 weapons, because the fast gear fill on all of them barely punishes you for quickly switching mid-fight.
There is a lot more pros and cons for all weapons, but it would get too much to list them all here.
I wished i had made more videos on JP, but i wasn't ever really a good player. I'd post stuff from my friend, but he's shy so here's some fast showcase of how dagger can circumvent a lot of dangers while still keeping on top with dps. This is of course doable with the other two weapons aswell, and they will be faster at it, but i wouldn't worry about it too much.
I do recommend using either knuckles or Dsaber for mobbing though, do yourself the favor it's a lot easier and stronger.