Is this stuff any good?

http://www.petco.com/Shop/Product.aspx?R=8...66&N=25+92&cp=5

i'm skeptical, but at the same time interested.

I would use the natural.

 

Merlin is on Zupreem natural (cockatiel size) and her feather has improved and she can't pick at her food anymore.

All three of my birds eat the natural cockatiel size. They enjoy it, and my vet recommended it, so I think it should be good