I read a chart somewhere with a bst and I think a monk figured out how much Subtle Blow works.
That'd get a new pet, Bst would check it's TP then release it. Monk would punch it, Bst quickly charmed it and checked it's TP, then released it. They would wait a while, and use different weapons and whatnot. I can't remember exactly how it worked, but something to this affect.
Enemy will recieve equal to your TP gain a round, +2. So if your a monk gaining 5tp a punch, hit twice, you get 10tp. So the enemy gets 10tp+2, 12tp. Subtle Blow takes off a certain portion of that, I'm not sure exactly how much, but some. For instance, it's each point of TP- 10%. So instead, you'd only give it 11tp. Not alot, but it's helpful in the long run. As you get more of these traits, it'll help more. I think monks get up to 4 Subtle blow traits, and let's assume each one is 10%. So instead of you giving it 12tp a round, it's now 8tp. A drk with a scythe gets about 12tp a round, so they'd give it 12+2, 14. Without the subtle blow trait, they're giving it alot more than a monk. But monks attack alot faster as well, so really the amount of TP given per job is about the same.