M.S.
I have always had lint traps on the top, and I like it there. I have used the other kind, and they don't seem to trap nearly as much lint in my opinion.
I have a Kenmore I got free from Craigslist in 2005 after they were done with it. It still works, but it clunks when it spins, only has heat or no heat, and it could use a tune up but it works great. I have no idea how old it really is, but I am leaning toward the 1980s sometime.
I am intending to get a new one because they are more efficient on electricity, but otherwise a tune up and this one would be good to go.