Great machine for the price.  Can't claim I've tested every single feature, but it does what 95% of buyers are going to need, and does it well.  Couple of little items that could be improved / fixed for cheap.   Needle screw - keep as is, just add a small triangle plastic thumbscrew over set screw.   Wouldn't interfere w operation, costs virtually nothing, adds 'quick change needle, no screw driver needed' as a feature.  Expand / improve official Brother YouTube guides.   Shouldn't have YouTubers doing better instructional videos for using your equipment that the actual company.   Or partner w one of them and make it your official.