Good luck with the DL1608. I purchased one last July(2013) with a grant from the Trillium Foundation, to help with some fundraising concerts and such. It has definitely done most of what I need and I have to say I'm quite satisfied. Some things to note, if you haven't already:
1) all the inputs are MONO in. This sounds pretty straight forward as most of your mics/instruments will also only send a mono signal. but if you try to run a cable from a stereo source ( like an ipod/mp3 player) and pass it through the combo input ( channels 12-16) your going to lose one of the channels. You need something appropriate to combine the channels into a mono signal, or a splitter to send 2 separate channels (not a copy of both channels) to individual inputs.
2) Read up on the Effects thread (reverb/delay) it will save you some frustration
3) Get a reliable router.
4) Download a copy of Voice Recorder Pro( its Free) if you want to listen to something you've recently recorded. The super odd decision by Mackie to provide no way to listen to something that you have just recorded is a pit of a pain.
5) Get a sign/shirt that says your working
You wouldn't believe how many people thought I was rudely playing games on the ipad during some of the awesome performances while I was mixing from the crowd!
Edit: also keep in mind, it is a tool. Like most tools, is probably does what it's supposed to do well, and it can do a few other things if needed, and if pushed, can do things it was not intended for. For example, a hammer is pretty good at driving nails into wood, it can also serve quite well as a paperweight, and if pushed, you can use it to cut a board in two (with extreme effort, and generally unpleasant results). The upside is that through software, some adjustments can be made regarding its utility, but it will have its limits.