It's not everybody's favorite, but it has to be a good one because I know of several who has the 319 as their favorite go to machine. It can be a bit more work to fix up a swing arm zigzagger than an old straight stitcher, especially DIY, but it's well within reach. Originally it took needle system 206x13 (easily ordered from the web) and even twin needle; some are converted to standard 130/705 needle.
You might have to make and effort when cleaning and lubricating it, there's lots of oil points, gears, levers and knobs, but with a few days of oiling, cleaning and test sewing it usually turns and shifts very well. I think the
Vintage Singer Yahoo group has a couple of members who use this machine. There's some general info on
this site.