The Helix provides spot-on emulations of 45 classic amplifiers, 30 popular cabinets, 16 mics and 70 effects. The black metal floor board contains 12 capacitive-sensing foot switches, an LCD display, an expression pedal, customizable LCD scribble strips, 6 "smart edit" controls, and a master volume and master headphone volume controls.
If that sounds like a lot, the I/O is extensive as well, with AES, SPDIF, and L6 digital outputs, a dedicated Variax connection so you can control Helix from the instrument, XLR, 1/4 inch and headphone analog outputs, 4 analog send and return loops, MIDI in and out, an XLR mic input connector complete with phantom power, external amp and expression pedal CV outputs, and a primary and aux inputs.
That's a nice feature set, but it's the sounds that really take the Helix to the next level. I was privileged to take part in a blind A/B test before the product launch. A number of classic guitar/amp setups were recorded along with a recording of the Helix emulation. I have to say that it was difficult to tell the difference between them, and I was often surprised to find out that the one I chose as sounding best was the Helix.
The Line 6 Helix is available in a floor or rack mount version and each sells for $1,499. Check out the great site that Line 6 has built for Helix for more information.