Helix's firmware has been pretty radically rebuilt and updated over the years, often by necessity because earlier versions weren't capable of supporting newer features or models. To be honest, we initially thought Helix might do okay-ish sales-wise, and we were trepidatious because of its 3x price jump from POD HD500X. The whole thing was supposed to stick around for 3, maybe 4 years and get replaced
(by something with my circa-2012 touchscreen-based design, the org assured me
), which was Line 6's MO at the time. But because Helix/HX has been so successful, we continue to squeeze an incredible amount of growth out of the family. Sometimes I imagine where we'd be had we
designed Helix to support 10+ years of updates, and... <sigh...>
My favorite Tube Screamer is UA's, in part because it was developed by ex-Line 6ers (and <shhh!> I was a beta tester). Ours could still improve.