I've had a couple of hyper-portable multifx units before (Korg Pandora MINI, Mooer Prime P1) and there is always a constant problem of quality. I don't mind excessively to this as I use these kind of machines mostly for exercising, when bringing guitar on holidays, for pre-stage warmup etc., but honestly, this time I was quite blown away by this machine.
1. the sound quality is absolutely good. Nux proves again able to write usable modelers
2. you can load custom IR
3. the machine is smaller than a credit card
4. it has bluetooth
5. with an unofficial app ("Mightier Amp") you can configure BT midi controllers like MVave Chocolate to operate it remotely
6. it can play backing tracks
7. you can even prepare cue points on the backing tracks to change preset
The only drawback is that the output is a minijack, so in case you want to go to an external PA you need an adapter from 3,5mm to 6.,3mm stereo jaack