I had an old Jet 16 for years. It was a good machine and worked well. It was a MT3 which I did not care for but it was never a problem. You do not need to worry about horsepower on a machine this size. The only time you need more power is when using large drill bits. I currently have an old Rockwell mill that has a 1/2 hp motor. I never slow it down. The Jet 16 has more quill travel than most mills this size which can be useful when boring lawnmower blocks.
There are a number of post here about small modifications to make it better. Better column clamp nuts, Delrin cross feed nuts, motor mount/ belt tension adjustment. You may find that the T nuts are an odd size, I had trouble finding any that fit right and ended up modifying some with a carbide end mill. You might also permanently remove the top belt cover. It was always in the way.
