Rabbinical Authority has nothing to do with if it is diet or not, nor does an "Organic" authority control the quality of the taste.  Authority systems address certain parameter.  There are many food authority systems outside of the Jewish religion.  If you are not Kosher then it might be a better idea to find a different standard.  Kosher standards have in the past protected animals from cruelty, but like all standards like even the US constitution... it has failed at times to live up to it's quality.  That said I am glad there are many varying Kosher standards for people to respect.  There isn't just one and that is a very good thing, because quality standards are not always upheld.  How many times have you heard of an elevator accident happening because the Elevator inspector wasn't doing his job?  Kosher Ethics can fail in the same respect... but we should not reject them because of the exceptions to the general positive impact that Kosher Authority has had on our food sources.  I'm sorry the brand you ate tasted like diet.  Perhaps you were attempting to brand the wrong standard.  The issue of taste is not a Kosher issue.  I recommend the Zagat guide.