I have a lovely newer Bernina that I love. However even the Bernina (known for lovely stitching) can't compete with my old machines for easy piecing. It is partly the narrow feed dogs and straight stitch foot plate, but the machines make it very easy to do good piecing. The old machines are also made for easy servicing. They do take regular oiling, maybe even every day, but it only takes a couple of minutes. Then they run and run and run - no adjustments needed, no expensive shop visits.
There are wonderful attachments for the vintage machines that duplicate many of the tasks you might think only the newer machines could do. I think the attachments are so much fun to use!
I do use the Bernina for much of my garment sewing since I like the zigzag function then. My piecing is done on a Featherweight mostly. I do have a new to me Singer 99 handcrank that I'm learning to use, and there is a treadle that is getting cleaned up. They just feel good.
Pam