So Ive read some threads regarding the matter now and wanted to discuss it more thoroughly.

When choosing between these 3 types, assuming you're mainly a sword-user, I'd say 2x medium increase sword damage-trinkets are the most worthwhile. Why?

Lets look at some numbers I got from the training hall (these are pretty much given in the wiki but whatever). These are the damages using Divine Avenger and Leviathan at lvl 10, using zero to maximum increase in sword damage against training-hall robots. I present the actual value first, followed by the % increase to widen the perspective a little since % is alot more interesting:

No Bonus:
DA: 43 Charge: 79
Levi: 39 Charge: 64

Low:
DA: 46 Charge: 83
Levi: 41 Charge: 67

Low % increase:
DA: 6.9% Charge: 5%
Levi: 5% Charge: 4.7%

Medium:
DA: 48 Charge: 87
Levi: 43 Charge: 70

Medium % increase:
DA: 11.6% Charge: 10.1%
Levi: 10.25% Charge: 9.37%

High:
DA: 51 Charge: 91
Levi: 45 Charge: 73

High % increase:
DA: 18.6% Charge: 15.2%
Levi: 15.4% Charge: 14%

Very High:
DA: 53 Charge: 95
Levi: 47 Charge: 76

Very High % increase:
DA: 23.25% Charge: 20.25%
Levi: 20.5% Charge: 18.75%

Ultra:
DA: 56 Charge: 99
Levi: 49 Charge: 79

Ultra % increase:
DA: 30% Charge: 25.3%
Levi: 25.6% Charge: 23.4%

Maximum:
DA: 58 Charge: 103
Levi: 51 Charge: 82

Maximum % increase:
DA: 35% Charge: 30.4%
Levi: 30.8% Charge: 28%

Just as the wiki says every damage increase lvl gives ~5% extra damage, totaling in a 30-35% increase using, for example 2x med trinkets + barbarous thorn shield. This means that every single hit will deal ~30% extra damage, every 3-hit combo using leviathan would deal "4 hit damage" instead.

In T3 however, you are usually not able to go around doing Levis full 3-hit combo without taking damage. At least not with the VH ASI increase I get from vog cub-set, the DA is another story because of its natural knockback, with ultra (mine's got UV ASI low) ASI you can usually get the 2 full swings in without much problem.

However, the most common thing is probably to do 2 hits -> shield / dodge with Levi, 1 hit -> shield / dodge with DA and so on. Using dmg trinkets (only) however, you will still deal ~20% extra dmg in every hit you're landing.

But of course the trinket which benefits you the most depends on your gear overall. Since Im using full vog cub I still get VH ASI increase, combining a with low och medium ASI increase UV will get you maximum speed increase + maximum dmg increase using dmg trinkets and barb. shield. It's easier to get the ASI or CTR from uv's since the dmg uv's on weapons can only be vs. certain types.

If you're using skolver however, I would probably choose 2x ASI and try getting a low or medium ASI UV on swords in order to still be able to shield ASAP after I've attacked. This would give the same stats as using vog cub, as long as its combined with barb. shield as well. However, using skolver you'd trade lower fire duration and normal / ele defence against lower freeze duration and normal / piercing defence. Of course it's up to everyone to choose, but imho the amount of piercing damage you face is ALOT less vs. elemental, especially in T3.

Going back to the trinkets though, I mean sure having high CTR is nice and all, I've seen the maximum CTR in action and its pretty fast and so on, but I still think using DA's normal 2-hit combo is alot more worthwhile since its still faster and still offers awesome crowd control. I wouldn't want to trade that extra second of less CTR against the extra DMG you could be doing with _every hit_.

In the end, of course alot comes down to individual playstyles and all. I just wanted to shed some light on the subject.