Nux MG-30

Current latest firmware: 2.5.06
Buyer be aware -- update your firmware as soon as you get the unit. If you make your own effects and then update the firmware, unit resets to stock effects.

NUX recommends you use the QuickTone editor app to backup your effects before updating firmware. However, my (and many others) QuickTone app could not recognize the MG-30 until I updated the firmware. So it was a catch 22 and I lost the 1 effect I had fine-tuned (not a huge pain, thankfully)

Pros:
+ FX Loop for 4-cable method for cheap -- I think the next MultiFX with a Loop is 50% more expensive
+ USB C, welcome to the future
+ This thing has an Uberschall, which sounds pretty convincing, and a Diezel, which sounds pretty crushing
+ Stock IRs are OK -- you can definitely dial in something fun and popping
+ Accepts 3rs party IR -- I already have my favorite IR on this thing and I am happy

Cons:
- Can NOT split L / R to have IRs on one end and off on the other (to connect to amp and line out separately). I wish they would add it with firmware -- if you need that, follow dev updates, I guess. The NUX Cerberus has this, come on :(
- Using it in the FX loop with 4-cable method degrades the sound a little bit. Steals high-end sparkle and adds a small upper-midrange hump. Forgiven, due to price, but beware if you want pristine signal!
- Can only load one IR at a time! Yes, when you are using the QuickTone app, you can set up a full library of about 20 IRs, but once you disconnect the NUX MG-30, it is left with the last custom IR you were using! Not a huge deal -- you are likely to pick the one IR you like best for playing live with. But, it does feel a bit stingy.
- As an interface -- I am not super-happy with the latency
- As an interface -- can't get true stereo, it seems the unit only goes to stereo for rotary effects
- As an interface -- Not enough options for USB and signal mix. I wanted this to double as an interface for my iPad (samples) as well as an FX unit on stage. However, USB signal mixing options don't allow for this. Can't be too mad at this price point! I was pushing my luck.
- I am worried how long those directional knobs will last
- Tiny wah pedal is uncomfortable for precise swells

I ended up returning this as it doesn’t meet my demands for live performance. It’ll do great for a starting musician or someone who plays mostly at home.

I am quite confused that NUX let the "youtuber presets" pass QC, if there was any type of QC?

The majority of the presets sounded so bad that I honestly thought my unit was broken. I was gonna contact Thomann after the weekend and request a return.
After that I decided to try and build some patches myself and imported some that I found in a Facebook group.
To my surprise the unit wasn't broken at all and the patches from Facebook were way better than the default ones.

So if you buy this and you think it sounds like crap... Try and import some patches or build your own. You might be surprised.

I have kept my unit and I'm happy with the sounds now when I started removing almost all the default patches. It as a lot of potential but you need to be willing to invest some time into building patches or finding other ppls patches to import. Also custom IR's make quite a big difference so I recommend trying those too.

It is a really good product with a lots of potential, however... QuickTone software and connecting to PC are very unreliable and cause the unit to hang and generate strange noises, and MG must be rebooted almost each time. To make it working with PC wasn´t straighforward also as promised. The driver(s) from Nux seem to be ureliable too and have problems with compatibility with other products it looks like.
Lack of touch screen is definitely a minus. The drum machine lacks metronome option. The drum machine can't be fully controlled outside the looper. When the looper is used together with rhythm and the looper is stopped, then the rhythm stops too.
The chassis and overall built quality seems to be quite good though. Nux could make the unit's chassis slightly bigger though and add two more footswitches instad of adding them as a separate controller, I think.
Interface is very nice and quite easy, though it takes a moment to remember all the tricks how to use it as each button/knob can be used for multiple options. Also working with the effect chain directly on the unit is not very intuitive in the fist moment, but it does not take long to learn it.
Expression pedal is set by default as volume pedal which is always on, I don't know why.
If Nux will fix and improve the QuickTone app and connectivity with PC, plus add metronome and correct, improve the firmware it might be actually a really great, small, portable effect.
Overall, good value for money.