Mac Mini vs. another Mac for music server

I've been getting into computer-based audio, and had been planning on picking up a Mac Mini for use as a music server. (Perhaps one of the new models, if they ever come out; maybe an older one that I could snag for a song once they've been superceded.) I'm currently ripping my CDs to a Dell laptop that is on its last legs, using a MacBook as the remote controller. I'm streaming to an Airport Express connected via an optical cable to a Cambridge Audio DacMagic feeding a Creek Audio Destiny integrated amplifier. (Speakers vary.)

My question: Does a Mac Mini necessarily make more sense than, say, a refurbished MacBook for a few dollars more? Is there a real advantage to using a Mini, sonicly or otherwise? (I'll most definitely be going with a Mac, as I'm now sold on Apple for a number of reasons.)

Is anyone using a MacBook (or an iMac or another Mac) as a server -- and doing so happily?

Thanks for your help on this.

Howard