I've had the Helix rack for some time. Been using it into my mixer and out of the studio monitors. But I wanted something that felt more amp-like, as in physically it feels natural to have the sound coming from one spot near the floor. Also, you can bend down and promote the feedback.
Well this does the job perfectly as it's made to accompany the Helix. Using it with the LINK cable, I can have the rack still going to the mixer and these speakers at the same time. Win-win!
The flat mode is the one I use as I have my presets with the cabs in them. Using the cab profiles in this unit sounds ok. I don't really hear much difference between them. But for those who do the option's there.
A bit pricey, but then it's a quality unit.