I still believe they all have their own sonic signatures, but they can all get the job done. I personally don't like the Helix but I know other people get great results with it.
The question is, how easy and how inspiring it is to use? I have always hated tweaking settings with a mouse/keyboard, and I'm sure there are others like me who want the hardware to be inspiring, so I believe the areas of biggest improvement, for all of them is in the UI. Touch screen is mandatory in 2021 imo. The QC ported a visual cab sim onto the device which is very cool. I'm curious if dragging the mics around on a virtual speaker is worthwhile or a gimmick? They could eventually have something like a version of Torpedo WOS in there.
I recently tried and returned a GT1000, largely because the UI was so bad. After using the touch interface of the G11, I just couldn't accept the GT1000. Even if it was the most amazing sounding box, it would have gone back. Technology moves so quickly you can't rest on your laurels.
What were you using prior to the QC? I've been reasing the thread on TGP and the only "real" issue I've read about is a ground loop type noise in some setups. It will be interesting to see how quickly they can add effects. My cheap(ish) Zoom G11 has a broad selection of different effect types, because they have been building these boxes for 30 years. You would think that the NDSP people would be able to "find" some algorithms to flesh out the effect section. Unfortunately, many of the Chinese boxes like NUX and Hotone come out of the gate with a ton of effects, likely because the software is pirated from some hacked device. NDSP would have to do it legally.
BTW you posted some broken links.
I think the links are ok now? I refreshed and I see them.
Honestly, it's very easy to use and just play with ideas on the grid. You can certainly get bad sounds out of it, but that's mostly user fault than any of the models or captures haha. I honestly find myself more inspired to play than I have been in a long time. I WANT to play with it, which makes me WANT to play guitar - that's actually a huge win for me right off the bat.
The cabsim and mics are good, in the end, it's just a fancy representation of many IRs blended and swapped in as you move the mics around - the IRs reflect the mics and their positions on the appropriate cab. So if you value and believe in IRs in general, and have spent time mixing and matching varying mics and mic positions from those and/or on real cabs - then it's more or less the same thing. I guess my point is - they're not "faking" it in the sense of trying to artificially adjust EQ or whatever to make it dull when you move off the dust cap - it moves to a real IR with that mic at that position on that cabinet and the response is what you'd get. They've just hidden that behind an intuitive UI, and you can still load your own IRs if you prefer - they're just static (as you'd expect) so no fancy UI - though you can still use a pair of them and pan them per cab block.
Previously I had my old ADA MP-2 (that I still love) and have had a few borrowed amps here and there for a time (mesas mostly) but for most recent things and anything I've recorded recently it's all been ampsims anyway (several from Neural which is how I found the QC in the first place, but others as well). I found the convenience and capabilities of modern ampsims to just be really good, it's nothing at all like 10 years ago or even 5. So in a way, the QC is just a larger commitment/transition to an "ampsim in a box" mindset for me. It's more powerful than any single desktop ampsim and its standalone portability makes it super attractive to me for when I visit my friend in LA and we want to play - I can have "my" entire rig in a carry-on bag.
I'm confident Neural will get the FX situation sorted out - what's there is good, they just lack for options compared to the competition, but it's very new and as you said, I believe they are doing it the "hard way" and not trying to just ripoff something and get shit out the door. I respect that, and if it's really a huge problem today, it's got FX loops - plug your favorite pedals into it, or even your favorite VSTs from your DAW - you can loop that in as well. Sure that last one isn't entirely portable (it is if you bring a laptop) but still - if you're worried about recording mostly it's trivial to get all the reverbs and delays and modulation fx you want. it's not a fatal shortcoming.
Bottom line - the cloud stuff is both great and awful right now - that needs the most work no question. The unit itself as a box that makes guitar tones - it's a joy. Honestly most fun I've had with any piece of gear in many many years. You just get lost for hours playing with it.