I wonder, also, what makes certain models more rave-worthy. I think of several factors when I rate my machines: stitch quality (straight separately from zig zag, satin, and decorative); tension; motor sound/feel; useful and unique features; and beauty. I can't underestimate the "pastel green"! I am also a sucker for shiny chrome and sky blue.
I would rate my Bernina 830e record and Bernina Minimatic 703 high on my list for motor sound/feel (although the mini is clackety on slow speed, with low torque selection), with good but not best straight and zz stitch. I like a smooth, quiet, powerful feel to my SM motor. However, I think my Elna zig zag, Singer 201-2, and Pfaff 260 have the most satisfying motor feel to me. For st. stitch, many machines are as good. The best zig zag/satin goes to the Elna and Singer 237. And, sad as I feel about it, I can't beat my Kenmore 158.1774 for decorative stitches and reliable tension. Kennie is just so homely!
For beauty, my White FR treadle, minty green Brother hand crank, blue and chrome Morse 4400. And the featherweight for cuteness.
Having said all that, the one that is currently set up for construction on my sewing table is the Bernina 830. Big Red is the only machine I have with a presser foot knee lift. That is why I scoured my sources until I found an affordable 830. The knee lift seemed so cool, but I haven't quite got the hang of it. Time will tell whether we truly bond, but my two cents goes with Cari: over-rated when there are so many other great machines out there.