The AX8 has the same 4 min looper. and the same fx loop to route fx blocks using 4CM...
Except as I said it's not the same, the Axe8, according to its manual has a Looper that is between 1 to 4 Minute Max depending on stereo/mono undo/no undo.
The Fx8 has 2 to 8 Minute max.
More importantly it is the same looper as in my Axe2 just more memory. Meaning it needs a block and changing presets won't keep the loop. That alone would have me want the FX8.
I explained above but seeing that you think the fx8 has an fx block I simplify...it doesn't. The architecture is not ax minus amp models. You have 8 fx that you can route serial or parallel, either through pre or post...no fx loop block there.
The set up I was describing was using a head with it going to cab and mic as well as IR loader.
If I wanted to do this with my Ax2 or an Ax8 it can't happen since with the 4cm it takes the fx loop block to rout the signal to and from the amps loop. Then I take the Amps direct out post power amp to the IR loader. Show me how I can do this without another set of I/o on the Axe2 or 8.
Lastly according to the Ax8 the Fx8 is optimized for unity gain, I've been using an AxeFx ( first ultra then axe2) for a decade in 4cm and Always had to deal with groud issues. On this even without humbuster cables no such issues.
As for the relays, having the ability to trigger stuff by scene change with the relays is what I missed since ditching the g system.
I have zero issue with you preferring the Ax8 but if you're advising others at least let's not change facts to fiction.