Incredibly solidly built and crystal-clear sound. It's simple, but it does what it's made for incredibly well. I guess it's fair to say that it's halfway between a mixer and a pedal -- and an audio interface.
Only complaint is the lack of headphones out. Granted that depeding on how the venue is set, an in ear monitor might be provided by the FOH, but I still maintain that it should have had an headphone out. This, and possibly the lack of mute/solo buttons are the only complaints of mine.
Other than that, all the rest is fabulous, and even the price, considering it has got a DI in it, isn't that much higher than what you would pay for a "normal" mixer and a DI box (or multiple DI boxes, if you've got more than 1 keyboard...). With the Key Largo, you simply hook your keyboards in it and you have a single balanced (and phantom power protected!) pair of XLRs out to feed the main mixer with. It's more convenient for the FOH (only a single input) and for the player, who will also be able to adjust his levels real time.
I use it for 3 keyboards, and I have a few pedals in its effect loops, all in stereo. Note that the effects loop can be set to mono, but if you do, both effect send and receive will change to mono, so you can't mix mono and stereo pedals in a single chain (not even mono-in, stero-out pedals).
