The biggest issue to me between the dl and the iX is that the hardware of the iX is something Mackie cannot step up to. The iX has 2 USB in/outs, midi I/O, and recallable preamps. All of which are extremely useful and all of which the dl does not have. It also has a built in power supply and we all know about mackies brick. Software it is better too. It has 4 fx processors right out of the box. I don't think the dl will ever have more than 2. There are also busses which hopefully Mackie will address.
So sticking with the dl you will never get what the iX offers.
A few thoughts on this issue I had when purchasing the DL1608:
1. I need a mixer NOW, as I already stated, not in some undisclosed time (probably September) when the ix16 is launching. By the way, to be fair, I waited as long as I could because the ix16 sounds like it is going to be one helluva portable iPad mixer. Others are probably in the same boat.
2. We really cannot be 100% certain what the feature-set will be between the two mixers. I mean, yeah, I, too am assuming the ix16 will have more features that will make it attractive, but categorically assuming that this is going to be that much better than the DL1608, AND assuming it will come in at the same price point may be a good bet but is admittedly premature. Look, I am not going to wade hip-deep into this whole vaperware discussion, because it is absurd and quibbling over the meaning of some obscure Internet-geek-speak term is...well, not an efficient use of my time. I would much rather jerk off to porn.
3. Since I bought the small mixer as a backup for my full band (to use now to get my feet wet) and as the main mixer for my acoustic duo, I also downloaded all the apps for all the mixers I am considering that can be mixed on the iPad. I downloaded the app for the StudioLive as well as the XiControl and the MasterFader app over a month before I bought the mixer. I have played with all of them, and while I (so far at least) absolutely love the X32, I have to confess that it is the WORST app for the iPad of all three mixers (SL, X32, and DL) to the point where I actually loathe it. Now this is assumptive on my part, but let me tell you this: I personally DO NOT care how many features the ix16 ends up having over the DL1608. If Behringer keeps that same app I downloaded and used already for the portable iPad mixer, that is an absolute deal breaker for me! I have become so familiar with the DL1608 software, and I have to say right now that despite all the bugs, the quibbles, the effects/compressor/limiter all being forced into the monitors, the position of the mute buttons, and a few other niggles, I absolutely LOVE MasterFader. It is, by far, the best iPad mixing app I have seen. Now if Behringer creates an app for the ix16 that rivals the structure of MasterFader, and the mixer is as good as you and others are predicting, then I can and will likely sell my DL1608 used for more than what I paid for it new (I paid $825.00 brand new and they are going for more than that used on eBay) and buy the ix16. But no way in hell am I buying an iPad only mixer with what Behringer has shown us so far on the iPad. I don't particularly care about the clunkiness and clumsiness of the iPad app for the X32, because when you have such a stunningly beautiful hard-mixing surface as the X32 has, the iPad app is sort of just a convenience or sweetener. I mean, I can go out into the audience to listen to my band and just throw a few faders. If I want to do anything deep in the mixer, say, then I can just do it at the console. Not an option with either the DL1608 or 1x16 because the iPad is the mixing surface. This is something that needs to be considered, again, assuming that we are getting the same or similar software to what Behringer has out now.
4. The DL1608 has been out for a while now (well okay 6 months or so?) and its faults are the subject of much forum fodder. Everyone is niggling and quibbling about it, right? I get that. We are all consumers and we shouldn't be blind fanboys, so all this shit is fair game. But what issues, problems, and glitches is the ix16 going to have upon launch? Do I really want to be Behringer's glorified beta tester for this coming mixer? Look, frankly, this mixer can launch without a single hitch or without anything that would be a show-stopper, I admit that. But what if it doesn't? Do I want to have a show for my band tank in the middle of my guitar solo or vocal passage and I can't do a think about it because I am singing and playing? Or maybe the software will have intermittent crashes that can destroy my band's show until Behringer works out the post release bugs that, for one reason or another, didn't get picked up during beta testing. All assumptions, I know, but it is equally assumptive to categorically say that the ix16 will launch without issues or problems.