FYI if you want help with review honesty, try sites like reviewmeta.com--it'll show you what percent of reviews are likely fake with certain metrics. The layout of the Juka machine looks weirdly simplistic, basic things like changing stitch length or width doesn't look as intuitive. You can't go wrong with any of those $130-200 Brother/Janome machines with literally thousands of reviews that come up with a quick Amazon search--plus, popular machines will have more reviews/tutorials/troubleshooting on youtube.

Unless your girlfriend is making crafts where she'd need some ornate leaf-pattern stitching, don't look into types of stitches as a measure of superiority. Unless she wants to sew thick wools, with the appropriate thread and needles, I don't think there's much variation in durability with those $100-200 machines. You don't need a computerized embroidery machine with fonts for garment construction; that being said, this one has lots of extra features for a low price if you think she wants to experiment.

My grandma uses this one, which I like because of the table (sooo much nicer working with more space)--but I'm guessing that's fairly standard for machines to have. Mine's a 30+yo machine from craigslist so I can't speak for modern plastic/computerized machines.

If you're still looking to spend around $400 for a gift, you could also get her a serger. It's absolutely not necessary for sewing, but it helps get cleaner sturdier stitches and things like rolled hems on delicate fabrics--but it's also a thousand times more complicated though (getting perfect tension/stitch sizing for different fabrics with 4 threads), I have a love/hate relationship with mine. Or had, before I let my grandma keep it and she gave it away to a needy relative.