Well, I kept the Mbox afterall.
I went to return it and get Sonar, and the salesguy that sold me the Mbox in the first place kept trying to talk me into keeping it. He sat down and showed me what it could do, went through recording a session and showed me how easy it was, and I was sold.
(Imagine that, a helpful salesperson at Guitar Center).
Anyway, I have recorded two songs with it completely and I think for my needs it works better than the 2488 did. It doesn't really sound any better, although I haven't used very many effects yet, but I just prefer the computer environment as opposed to the 2488's console environment. Plus I'm never going to need more than one input at the same time.
I appreciate everyone's help on this.