Interesting because my Halo juices always perform. Either which way, the answer to your question is performance. Lasttango and Dr. V are the two posters that I have read hammer this point home, and though it took awhile to set in with me, PERFORMANCE always is the best attribute of a liquid.
I used to love Halo's P15 (mid last year) but left it alone in lieu of a flavor search; but I recently realized I needed a juice to perform consistently, so I went back to P15 and the love affair was rekindled.
Of course, the term performance is virtually all other categories wrapped up into one, but it still can exist as a entity unto itself. For me, Halo Prime 15 is my best performing juice to date--and I do mean out of all juices I've tried.
edit***On second thought, the answer to your question is unknown. Some juices are just perfectly blended with the right amount of everything and none of anything else. I think a lot has to do with hardware though.