I'm not gonna read the 174 pages of this thread.
Short story: I REALLY like it so far.
Long story:
I just bought an HX Effects last year to pair with an Atomic Firebox for my guitar needs, as a backup for my Avid Eleven Rack.
I pre-ordered a Tech21 YYZ MF40 (40th year of Moving Pictures limited edition), for no other reasons that's because of Geddy Lee if I started on bass. I told myself that I could pair it with the HX Effects for my (very limited) effect needs and also as a backup to my Eleven Rack for bass. But the YYZ couldn't be the sound I want for every songs so I looked at the effect models on the HXFX and discovered there's the Zeroamp (BDDI), the Obsidian (Darkglass B7K), the Ampeg Scramb(l)er, and some EQs. I listened to countless BDDI reviews on youtube in the past and it was not my cup of tea at all, but decided I can give it a try knowing I'm more an Ampeg SVT guy.
OMG: this is the perfect sound I was looking to complement the YYZ. More than that, I can definitely gig with just my HXFX. Putting a Simple EQ after the Zeroamp to add the missing mids. And with the Ampeg Scrambler, the LA Studio Comp, the Bass Octaver, the Tilt and the builtin tuner I'm all in!!!
I'm not sure how close the Zeroamp is to the BDDI but I don't mind as I like the sound a lot, just wished now that Line 6 update the model to BDDI V2 to add the mid control.
I'm ampless for the last 15 years (started with a Peavey tube preamp and then Eleven Rack) so I'm used to direct to FOH sound. The HXFX has everything I need and even more. Really a nice piece of gear. And with the POE plug I made, I'm not tied to have an AC outlet within 1 meters to power it.