I've had the Zoom B3n for a year now, and gigged regularly with it.
After hearing The B3n side-by-side with The Line 6 Helix stomp - there is
no comparison!
The Helix effects eat Zoom's effects/sims for breakfast, lunch & dinner!
Even the ability of The Helix for midi & effects loops, which adds very important connectivity & versatility (Zoom will
NEVER get this part right, as they don't listen to customers and are too cheap/unmotivated to do so).
Look just how big The Zoom G5n is - and still
zero midi/fx loop connectivity on its empty input panel!
There is a depth, responsiveness, fidelity, and connectivity in The Helix line that Zoom effects just cannot touch.
The Zoom sounds nice, until you place a Helix next to it for direct comparison - that's when the difference becomes abundantly clear - that there is a
big difference in class and realism.
But, there is also a difference in price + $/£300!
The ONLY reason I've stuck with the Zoom B3n is because of Zoom's vastly superior 6 pedal switching capability.
It's hilarious to me that people mention how great it is to have a Micro-Helix, but the first thing they all have to do is buy an additional switching pedal that
doubles its size - just to be able to use it on a gig!!

A Zoom 'B3n-sized' Helix Stomp, with 6 pedal switches, would be the perfect size for a MultiFx (+ nobody would need an additional bulky footswitcher pedal just to use it).
If you are used to switching & scrolling effects/patches on the fly, the Helix Stomp is embarrasingly poor.
But, if you are a "3 patches only/set at home & forget" kind of guy, then the Helix is vastly superior (in my opinion).
Even the guy who started this thread (Charlie C), has sold his zoom b3n, bought a Helix stomp, and hasn't looked back!!.....