I'm glad you picked the R24, because it's a worthwhile upgrade over the R16, which I've had for over a year. I'd love to have those extra tracks and the drum patterns. These are great machines IMO, but for me the learning curve was pretty steep for using the effects, editing the mastering algorithms, using even the basics of the included Cubase software, etc. If you're already competent with DAW software, plug-ins, and the like, it will be easier for you, but I've tried to get the most out of the machine itself. The versatility is just incredible, and IMO the audio quality is excellent.
I highly recommend visiting zoomforum.us, in which some users, notably Kevin Selby (Selbelicious) have posted extremely helpful tutorials. Kevin's post about editing the mastering patches saved a couple of my band's tracks. I also learned about a firmware upgrade that solved a bug in the original R16 (effects disappearing when recording to the master track), which was also a lifesaver.
Also, be careful about using the "divide" function on individual tracks, because at least on the R16 it doesn't always work properly. Experiment on tracks you don't need, or copy them before trying to divide them. Hopefully it works better on the R24.