I know many people are tired of these but I like them. I do take them with a grain of salt. I'm never looking for a representation of what the units sound like with these. As many of us know, there are too many variables to make a determination of that. But I like seeing/hearing how close they can get to each other. It is interesting to me. Then again, there is a good chance I may be just looking for validation of my purchase choice. In this case, I closed my eyes before I could see what was what, listened, and when I opened them, I actually liked the Helix tone slightly better. Only VERY slightly though. They were all extremely, super close. And maybe with a little more tweaking, even closer. They were all so close, it would be hard to determine from this, which one to get. They can get so close to each other that it has become more and more apparent to me that none of these are better than the others. It's more about your work style, flow and what exactly you want to use them for.
To me, the Fractal and Helix are essentially studios in a box with the Fractal having a little more finesse and options. Which you pay for. I think the Helix is right on it's heels though. The Fractal is less user friendly but that certainly doesn't make a difference to me personally. I think it does to others. And I would say the Helix (the floor unit anyway) is built more for the average bar, small venue, gigging musician, where the Fractal is more for the concert type, "big time" situation, (less drunks and spilled beer to worry about). Not that they couldn't be used for either situation. Not at all. There is a rackmount Helix after all. They both are more about getting a studio sound in the field.
The Kemper seems to be more about having an amp in the room experience. Or more to the point, ANY amp you want in a room experience. Less about a studio sound in the field. A VERY cool thing. All have their place and are of equal value. Just each with their own strengths. And of course, as Dunedin pointed out, your average shmo has no clue and more than likely, would say they all sound the same. But, they don't have to have a clue and don't want to. They probably don't even care. I know, I know...not care about guitar tone? What's wrong with them?
What a GREAT time to be a guitar player. I just wish it had happened about 30 years ago. Sigh. Wait. How old am I again?