If you're using one of the devices that it's pre-programmed for, it looks great.
If you're using it for something else, such as DAW control, then know in advance exactly what you want each pedal to do in each mode (write it out!), and push your pedals till it does what you want.
Questions I'd ask would be:
Once I've got the PP Mode set up, can I DL the configuration and restore it later (in case a factory reset is required)?
Can it send a Stomp configuration on preset load?
That's all I can think of off hand. It looks like a really good upgrade, IF the PP configuration can be saved/restored. Otherwise, if that's the mode I'll be using most, I'd stick with UNO.