Who knows, maybe despite my searching - I'll get called out for a noob first post... but truly can't find the definitive answer.
For awhile now Torrie has been offering a GTX tuning package, and I found at least one post of a SHO owner selling their used GTX - but hardly any discussion of anybody's actual experience with it. A few people upgraded to the Livewire, but seems like most people have stuck with their X4's.
But aside from personal experience, anybody know if it's even compatible with pre-2015 models? According to SCT, it's not supported at all - but since I'd never be using one of their tunes anyway, I figured a tune from Unleashed or Gearhead wouldnt care which hardware it's being loaded through... but just reached out to Matt about it and the response was that the GTX is definitely not suggested for my year (2014). Specifically, that it would "work," but that I might have trouble changing tunes or reverting back to stock with the GTX.
Obviously the tune is more important than the tuner, but I definitely wanted to take advantage of the live gauges... and I know I know, I could just get the livewire and not worry about it - but now that the GTX is finally out, it just seemed a little bit better in every way.
I'll probably send a quick email to unleashed too and see if they've developed some work-around; who knows maybe as soon as you complete the order with a pre-2015 model year it doesn't go through.
Thanks guys, I'll update with whatever I learn in case anybody's curious.