I have two Vikings. One is over 30 yrs old, solid metal case and works great. The other is a Diamond 20 about 1-1/2 yrs old embroidery machine. While I don't know yet how to use the embroidery module, I love the machine. And it never needs oiling.
The problem is that like everything else, it cost too much to build a good quality product. Most everything nowdays is built in China, Japan, Taiwan, etc. And while we know their quality is not always the best, we continue to buy the junk. I say research any machine you are about to buy. Janome is a good one, Singer was the best years ago. Preserve the old metal machines. They will outlast these new plastic ones with plastic gears