I'm not so sure its totally about the quality of the extract as its about my preference for beer flavored beer. When a beer has a flavor I generally like it to be subtle and complimentary. For instance I just put an entire grapefruit, skin and all, through a juicer and added it to the fermenter of a cascade and centennial dominant IPA along with some fresh Rosemary. (Yes,I'll tell anyone who tries it that it contains grapefruit
)I am expecting those additions to add noticeable but not overpowering aroma and flavor contributions. IME the beers I have had that add "flavors" other than the natural whole ingredients tend to be too much. For my personal taste, maybe others don't find grapefruit sculpin for instance to be ruined or close to it by the perfume like aroma.