I recently saw a ToneJunkie video podcast where HW and Michael Britt were discussing the advantages of Kemper over Helix and Axe etc. One of things they mentioned was that the other solutions try to totally emulate the physical amps INCLUDING their shortfalls. One example given was that on a real amp the gain and volume are interdependent. Turning up the gain means you NEED to turn down the volume to retain the same level. The team at Kemper took a different approach and captured all the good bits but improved upon the shortfalls In this example they made it possible to increase gain without needing to reduce volume. However, if you want to increase volume you still can but it's a choice.
I never knew that! But now I think about it....