This is a very, very interesting comparison for me. After spending a year with my HX Effects, I'm totally in on the capabilities of the Helix platform. Hey, if the HXFX can breathe new life into my ancient Tech 21 Trademark 60 (TM60), that's a huge win in my book. My TM60 is set clean on channel 1, and my favorite "pedalboard" lately features the Tone Sovereign, and using Snapshots to change Tone Sovereign settings without having to twist any virtual knobs... love it.
That said, I've been looking for ways to overcome some of the limitations inherent when using stomps with a clean amp (or an amp's clean channel, as with my TM60). And, after a year with it, I've found I've settled in to using just a few templates overall and, surprisingly, a lot fewer effects than I thought. The "limitations" of the HX Stomp suddenly aren't as, well, limiting.
I could definitely see myself moving up from the HXFX to the HX Stomp, with the full amp models with cabinets with mics taking the place of the "pedalboard foundations" I've created for my HXFX. I don't use expression pedals (yet) so that's not a factor, and I don't have other effects pedals to patch in as that was the point of getting the HXFX in the first place. :) I could probably get away with using a 1/4-inch outputs from the HX Stomp into the effects return of the TM60, as the Celestion 70-80 speaker in there is pretty neutral (to my ears, anyway) and it would probably function well enough as a monitor, sort of like Tech 21's Power Engine combos.
Additionally, I dabble in playing bass as well, and would play it on anything I choose to record, likely using the Stomp as an interface (just like I used to with my GuitarPort!), so... more points for HX Stomp.
Thanks for this informative post. Interesting, indeed.