I am still on the fence. I've found a combination of 2 cabinets in the Helix that I'm working on that is open and alive, but not quit to where I can say better than IR's. Not all IR's are good but I have some blended versions of both mic and speakers that I really like. That and setting low cut between 50-120 and high between 5-10 really make a huge difference. I am extremely impressed with the Helix and find it is very close when comparing to my amps and Kemper. I was skeptical, but the skepticism left the first day.
I have a preset with the method above, a dual cab and an IR and I'm still working on the conclusion.