I don't get it...I love my Realtek's and use them all the time for various things. They are all I use on all my service boxes and my laptop. I'd not compare it to any of the super great cards I have...but I don't understand why everyone bashes them. Use one with asio4all in Sonar and it works perfectly and can go down to 64 buffers without a problem, glitch or hiccup.
This isn't perfect as I just did it real quick as a goof while beta testing a bunch of stuff. Worked on the mix for about an hour....but here is Sonar, a Realtek, a Mackie 32x8 and me being me doing a cover of Daughtry's "Over You".
https://dl.dropbox.com/u/4909348/OverYou2Master16.mp3 It's ok if no one likes it...that's not the point. The point is, I've heard WAY worse from people that are better engineers than me using far better gear. This sounds pretty acceptable to me for what it is and I dig how it turned out...even with a Realtek. *shrugs*
Would it have come out different using my other cards? I'm sure. Would it be better? I would say no...just "different". It's only going to record what you send into it.
-Danny