Well your "test" to me lacks any validity. The reason is that you went into it with an expectation or a bias.
i bet that you had huge hopes and dreams for your sparrow based on all the hype and exaggeration created here (which I agree with you is ridiculous)
Then when you finally heard it you were disgusted that it sounded basicly the same as your onboard soundcard.
In that frame of mind you conceived the idea to perform a "double blind" test to prove what you had experienced. Not surprisingly you couldn't tell a difference as you didn't want to be able to.
Just a theory... now a valid test would have been if you used some1 who had no bias but who also has a discerning ear when it comes to audio.