I have an 4 year old "new computerized" Brother machine - Love it! But I also have GREAT vintage machineS that are smooth and quiet and make beautiful straight stitches.
I also love the knee control feature on the Singer I'm using to piece some Texas Braids on. I keep telling myself I'm exercising my thigh while I sew! LOL Now I only have to figure out how to sew with my left leg so it gets the same workout! ROFLMBO
IMHO: If the machine runs quiet and smooth and makes beautiful stitches - clean it up, set it up and use it!