I've tried grafting with the Chinese tool, the JZsBZs, and German stainless steel. They each worked, but I prefer the JZsBZs or stainless steel, I just don't seem to be able to get consistency from the Chinese tool, sometimes it works just fine, sometimes I don't seem to be able to get it to do what I want it too.
With the JZsBZs, I can just hook under the larva, like C< and with the German stainless, I pick them up like >C. I find that with the JZsBZs it is a little easier to not flip the larva. I have come to realize that if there is even the slightest tendency to "fumble" with the larva, that larva is already lost --> time to move on to another larva.
I also prefer to prime with fresh royal jelly stolen from an older, but not yet sealed sister cell. For me the larva transfers from the needle to the droplet of jelly with less chance of fumbling or trauma to the larva. I just pluck out the older larva, steal the jelly needed to prime with, move the sacrificed cell to my new bar, and re-graft it too. I only use single bars with between twelve and fourteen cell cups. My bars are mostly grooved top bars that I've trimmed down on my band saw so they are very narrow, some are customized so they are three or four inches wide, that way their cells are positioned about midway down the medium depth combs they are sandwiched between - hopefully providing them a slightly better environment. Only rarely has a cell been partially attached to a comb face. I've gotten the largest and best fed cells when I pull a comb of just hatched larva immediately before placing a newly grafted cell bar, so I try to make that happen as often as I can. I shake the bees from this comb as I remove it - leaving them behind.
My eyes are fifty-four years old and diabetic, so even when grafting outdoors in daylight I wear a bright LED headlamp focused to illuminate the cells I am looking at. I also wear a pair of high-powered reading glasses, over my corrective lenses, when using both the LED and magnification I have no trouble observing the entire grafting process - I know immediately when I've fumbled one, and can then drop it, wipe my needle and move on to the next.
I haven't tried the 000 paint brush, yet, but I believe I will try it too. I sometimes get 100% takes, but it's more often about 80%, and sometimes 0%, though when it's that low, I can usually expect to find a rogue virgin killing my freshly grafted larva. The virgin queens don't just tear holes in sealed cells, they destroy younger grafted larva, too. The first time a rogue virgin was responsible; every day, for three days, I would re-graft the cells, then when I checked on them the next day, nada. On the third day, when I pulled the bar, there she was, and she was still intently focused on her business of killing/removing the young larva from my cell cups. Arrgh. I quickly convinced her to stop killing my grafted larva.