I had the BE and Helios at the same time. Kept the BE. Helios IS a great amp, but BE gets the edge.
The BE can do what the Helios can and way more, IMO. It's just more versatile. The two inputs on the Helios are a pain in the ass if you want to switch from clean to high gain. You have one choice, high or low input, so one will affect the other when switching channels unless you change the input manually.
The Helios is a little more raw Marshall, which I liked. However, the new 2016 BE updates make it more raw and takes care of that. I had a high/ low voltage switch added to my BE, which makes it even more raw.
The BE has more options. BE/HBE, SAT, FAT, c45, voice switch, gain structure. A better clean channel IMO. And for me my favorite thing about the BE, and Friedman amps in general, is the support from Dave. It's really easy to get ahold of him and I've had him make tweaks to my amp at least 4-5 times to make it sound how I want it. I literally walk in his shop, tell him what I want and he always says, "Sure, no problem." I've had him update the caps, change the clean channel to the SS100 circuit, add a gain structure switch, voltage switch, change to the newer TAD tubes, all kinds of stuff.
The BE is my #1 amp and I have many. It's at Dave's right now and I'm having separation anxiety until I get it back. Fantastic piece of gear.