Well, considering you can't burn an audio CD at 24-bit and have it play in Chuck Ufarley's CD player it really comes down to the dithering software. I agree that 24-bit is better. If you know how to use the tools in your studio correctly. I crappy recording in 16-bit is still going to sound like crap in 24-bit dithered to 16. Once you get a recording in 16 that is close to what you want, venture into 24 to hear the differences on your final mixes.
I agree with you littledog, but jumping up and forking out the cash for a full 24-bit system for someone who doesn't know about it throws up the flag that he needs a few more years under his belt in the 16-bit realm. It was still a good question though, and no offense intended towards you littledog.