I will also jump in here and say that I used the bulk system on my HM1 the whole entire time I owned it, and because I had the proper environment that I kept a certain temp as well as humidity, I never had any issues with it at all. I never had head clogs, and always got great coverage. There are many pictures from me on this forum of garments I printed over the years to show this.
I think that some times what works for one person may not work for another, but its figuring out what works best for you.
I think that Dupont does have the best white ink, and that is because they have continuously changed it over the years to get a better ink. When I first started with their original white ink, it separated very quickly, and every time they make a new formula for improvement, it gets better as it did for me. I will say I never used the bagged system because I did not have any issues with the bulk system, and my theory was why fix it if it was not broken. Remember that anyone coming out with new white inks, are going to go through the growing pains dupont did to get it to the level dupont has gotten their ink.
As Carla stated, even though the ink they are using is DUPONT, it is packaged differently, but still the same ink. So is there a better white ink than Dupont? Probably not, as the other manufacturing companies of ink, have yet to go through all the growing pains they did, reformulating to get a better ink over and over. They start with one formula, figure out a way to make it better and so on and so on until they get to where Dupont is.
I know there are several different ink sets for CMYK that may work well, but with the white I had never found a better ink then Dupont. The packaging of it just depends on you, and what works best for you. For me my bulk system was perfectly fine and I never felt the need to change it, as I had absolutely no issues with it. So it really comes down to what works best for each individual but as far as brand, I think dupont is the best white you will find.