Here's a quick update. (and this is not a recommendation or endorsement). I picked up a SoundCraft ui16
The appeal for me was that it was one of the few that allows you to control it from a browser. So far it works with every device that I've tried (Surface [many models including the original Surface RT], Windows phone, and several others].
It has it's own wifi router (only 2.4), it can connect to an existing wifi network, and it allows for a hardwired connection. I haven't dug in far enough to know if I can connect another router to this, but the first two options seem pretty good.
In addition to the main left and right outputs (XLR and ¼ inch jack Tip-Ring-Sleeve ) there are four Aux outputs. That means that at most, you've got four individual monitor mixes.
It's called a ui16, but it's got 12 XLR inputs (8 or which are combo jacks). Then you've got a couple of RCA inputs and you've got two more inputs if you consider that it will play audio tracks directly from a USB storage device. Interestingly you can record to a USB storage device (stereo mix no individual tracks).
This is a small mixer. I think this would be fine for a four piece band running through a pair of F1 Stacks (Model 812 with F1 Subwoofer) x 2 if you don't mic all the individual drums.
There's a cool feature that I hadn't noticed when I was comparing units. On the first two channels there are Digitech guitar amp emulations. These will not replace my Kemper, but they do sound pretty good. I could certainly get through a gig if I had to do it without my Kemper. (Yay - I've backup built right in, in the mixer).
This is my first foray into this kind of technology and I wasn't ready to plunk down a lot of cash. The Behringer XR18 was close to double the price and it did have more channels, and more features. For what I need to do right now, it looks like the SoundCraft will do, and it was so inexpensive, there was little risk.
On the downside - there are no ToneMatch Presets. This means that it will be more work to set things up to get great sound, but there are some nice tools built into the unit. I'm just going to have to dig in to figure it all out.
I'm doing a private event in a couple of weeks. It's small enough to do with a couple of Compacts. I've been asked to be prepared for up to six performers at a time. I've done lots of events like this with a couple of Compacts with two T1®s. I'll definitely take the T1®s this time (backup), but I'll probably take the SoundCraft ui16 to give it a run.
Thanks to everyone who offered suggestions. I'll let you all know how it goes.