Yeah, I'm using the VDI connection...not sure why I feel like I need to keep the Helix, other than it has served me very well since I got it! I could plug my vocal mics directly into my interface and just use plug-in reverbs, compressors, etc. and I am sure I could just run the Variax into the Kemper and use the lithium-ion battery that came with the JTV guitar. Both being Line 6, the JTV and the Helix play very nice together though.
I'm definitely learning my way around the KPA after a week of having it, but the Helix is just a much simpler device to use and I really miss having the editor on my Mac...I used it as my main interaction with the Helix...I kept the Helix on the floor under my desk so rarely had to actually access it with my hands and the editor was just the best way to work with it and still use my feet for the expression pedals. I also think it was easier to dial in the effects on the Helix than it is on the KPA, but that will probably become easier the more I work with the KPA. I loved being able to blend two different amps together on the Helix, but I understand that the Helix & the KPA are two different kinds of beasts...which is probably another reason I kind of want to hang on to the Helix...neither is a direct replacement for the other.
The Helix has the ability to make the footswitches either latching or momentary...does the KPA have that sort of feature? (I found that using a harmony setting with a momentary footswitch was handy for recording leads...I could be playing and simply press & hold for a quick harmony run and then release to go back to single guitar.)
I could see in the future just moving the Helix to the living room with some kind of powered FR speaker and using it as a "couch amp".
I had a great weekend with the KPA though...I finished two tracks to wrap up my next "EP" release on bandcamp.com and recorded the first track for the next EP! New toys always spark the creativity! The new delays in the latest update are great...could better reverbs be coming? (some of the reverbs are quite good though the Helix has a lot of really nice reverbs.) Do I understand correctly that Kemper is pretty good about continually issuing updates?
The Helix has a nice group of guys in the forum and this forum seems great as well - doesn't seem to be any bad apples like you see in just about every internet forum these days...that's refreshing!