Zupreem has lots of added artificial coloring, flavors, and sugars. Like I mentioned, I would try it as a transitional food, but not the permanent pellet brand. Zupreem's "natural" versions might be OK. I always used Roudybush as it is what a breeder I knew used and just knew it to be a good brand.
Harrison's is top of the line if I remember correctly. Supposed to be even better than Roudybush. Don't just take my word for it though, google/research it as I don't know if I remembered correctly or not!
If I were you, I would use the seed to transition to pellets (I'm not one for wasting food, even when it's not the best stuff. I use it up) and save the nutriberries as treats. One per bird per day should be plenty.