Once set up and configured correctly the Helix range sound great.
There is quite a bit of a learning curve however, so if you need something to just plug in, twiddle the knobs and go, this is not for you.
Firstly, the stock cabinets suck. they are terrible.
This means you need IR's (Impulse Responses).
Simple explanation is: IR's are the sonic footprint of a particular configuration of gear, but usually various cabinets mic'ed up in different ways.
Line 6 gives a handful free but the best are by a company called OwnHammer, and need to be purchased on the line 6 marketplace at additional cost.
This has meant that its taken a few days to get any reasonable tone out of it.
Second issue is connecting to the pc.
It took a while to find the right drivers and even then, the device seems to need to be " in the mood" to connect. An hour or two got it connected.
Lastly, a big issue is how fussy the device is with USB Ports.
It wont work when plugged into a USB Hub, even a powered one. It keeps disconnecting. It wants dedicated USB ports in a pc.
I have a laptop that has very few connectors, but I use a dock for all the ports i require. Even with the docking station, the stomp disconnects randomly, often during data transfer of IR's or firmware updates.
It works when connecting to the pc, but its just not as solid as I expect. Could never be used live with a pc attached.
Other than that, its pretty good. I think its a tad overpriced but not by a crazy amount.
Overall a decent device with some quirky behavior and requires a lot of effort to get tone out of initially.