Hi Joe,
I have a 778, purchased in 1976. i think it has metal gears, very heavy machine. It has cams for fancy stitches, but I do not like results of all the cams. Some I love. I have used it for dress making and now for quilting. As long as I keep bobbin area clean & oiled it sew great. Since I retired 4 yrs ago it has gotten very heavy use.
When I purchased it, computerized machines were just starting to be on the market. I told sales person I wanted one that did every thing the "fancy" ones did but not the computer(I did not trust computerized maschines) At the time this machine was the top of the line. Because it was so expensive I do not see many. It has a slant needle and low shank. I have yet to find a walking foot that will work on it. I have 3 walking feet. I have had to replace the foot pedal recently, original was getting to warm for me, did not want to take a chance on a fire.
My DH takes it apart and cleans & oils innards periodically
Hop this helps.