Needle threader.
Thread cutter.
Knee lift.
Extension table.
Sturdy, reliable, mechanical machine, no computer boards or chips that are cost-prohibitive to repair/replace.
I have all of these in my Brother 1500. I realized since I acquired it, I haven't touched my other machines, so I sold or gave away all of them except for my Pfaff, which has a buttonhole stitch (and I actually use it for buttonholes!).
A lot of people complain that the needle threader on the 1500 doesn't work, but time after time it turns out they didn't understand *how* it works and so were using it improperly.